Risk/Return Detail Data - FidelityAdvisorIndustrialsFund-RetailPRO - USD ($) |
12 Months Ended | 60 Months Ended | 96 Months Ended | 120 Months Ended | ||||||||||||||||||||||||||||||||||||
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Sep. 29, 2026 |
Sep. 29, 2026 |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Sep. 29, 2026 |
Sep. 29, 2026 |
Sep. 29, 2026 |
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| FidelityAdvisorIndustrialsFund-RetailPRO | Fidelity Advisor Industrials Fund | Select Industrials Portfolio | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.63% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.01% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.64% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 65 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 205 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 357 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | $ 798 | |||||||||||||||||||||||||||||||||||||||
| FidelityAdvisorIndustrialsFund-RetailPRO | Fidelity Advisor Industrials Fund | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Risk/Return [Heading] | Fund Summary Fund /Class: Fidelity Advisor® Industrials Fund /Industrials Portfolio | |||||||||||||||||||||||||||||||||||||||
| Objective [Heading] | Investment Objective | |||||||||||||||||||||||||||||||||||||||
| Objective, Primary [Text Block] | Fidelity Advisor® Industrials Fund seeks capital appreciation. | |||||||||||||||||||||||||||||||||||||||
| Expense Heading [Optional Text] | Fee Table | |||||||||||||||||||||||||||||||||||||||
| Expense Narrative [Text Block] | The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. | |||||||||||||||||||||||||||||||||||||||
| Shareholder Fees Caption [Optional Text] | Shareholder fees | |||||||||||||||||||||||||||||||||||||||
| Shareholder Fee, Other | $ 0 | |||||||||||||||||||||||||||||||||||||||
| Operating Expenses Caption [Optional Text] | Annual Operating Expenses | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Heading] | Portfolio Turnover | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Text Block] | The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 34 % of the average value of its portfolio. | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover, Rate | 34.00% | |||||||||||||||||||||||||||||||||||||||
| Expense Example Narrative [Text Block] | This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: | |||||||||||||||||||||||||||||||||||||||
| Strategy [Heading] | Principal Investment Strategies | |||||||||||||||||||||||||||||||||||||||
| Strategy Narrative [Text Block] | Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, distribution, supply, or sale of industrial products, services, or equipment. Industrial products, services and equipment, such as capital goods, construction services, machinery, commercial services, and transportation, are generally considered to be sensitive to the business cycle. These companies may include, for example, manufacturers of civil or military aerospace and defense equipment, building components, and home improvement products and equipment; civil engineering companies and large-scale contractors; companies that produce electrical components or equipment; manufacturers of industrial machinery and industrial components and products; manufacturers of agricultural machinery and equipment; providers of commercial printing services; companies providing business support services related to human capital management and office supplies, providers of commercial data processing and business outsourcing services, environmental and facilities maintenance; companies providing transportation services, including airlines, couriers, marine, road & rail, and transportation infrastructure. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. | |||||||||||||||||||||||||||||||||||||||
| Strategy Portfolio Concentration [Text] | Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, distribution, supply, or sale of industrial products, services, or equipment. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | Performance | |||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] | The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of Class I , a class of shares of the fund, from year to year and compares the performance of this class to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information for Class I , a class of shares of the fund. Performance history will be available at www.fidelity.com for Industrials Portfolio after Industrials Portfolio has been in operation for one calendar year. | |||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The information illustrates the changes in the performance of Class I , a class of shares of the fund, from year to year and compares the performance of this class to the performance of a securities market index and an additional index over various periods of time. | |||||||||||||||||||||||||||||||||||||||
| Performance One Year or Less [Text] | Performance history will be available at www.fidelity.com for Industrials Portfolio after Industrials Portfolio has been in operation for one calendar year. | |||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | institutional.fidelity.com | |||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | Past performance (before and after taxes) is not an indication of future performance. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Year-by-Year Returns | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Returns for Class Not Offered in Prospectus [Text] | * The returns shown above are for Class I, a class of shares of the fund that is not offered through this prospectus. Industrials Portfolio would have substantially similar annual returns to Class I because the classes are invested in the same portfolio of securities. Industrials Portfolio's returns would differ from Class I's returns only to the extent that the classes do not have the same expenses. | |||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | Year-to-Date Return | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 23.39% | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | Highest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2025 | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 20.16% | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | Lowest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (28.74%) | |||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average Annual Returns | |||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). | |||||||||||||||||||||||||||||||||||||||
| Performance Table Explanation after Tax Higher | Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Narrative | After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| FidelityAdvisorIndustrialsFund-RetailPRO | Fidelity Advisor Industrials Fund | F1511 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | MSCI U.S. IMI Industrials 25-50 Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 18.63% | 13.48% | 13.27% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorIndustrialsFund-RetailPRO | Fidelity Advisor Industrials Fund | SP001 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | S&P 500® Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.88% | 14.42% | 14.82% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials Fund - Class I | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.67% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.02% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.69% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 70 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 221 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 384 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 859 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 70 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 221 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 384 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 859 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 24.77% | 14.67% | 12.77% | |||||||||||||||||||||||||||||||||||||
| Annual Return [Percent] | 24.77% | 23.35% | 22.99% | (10.39%) | 16.92% | 11.48% | 28.09% | (15.34%) | 19.87% | 15.77% | ||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 5.75% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [1] | 0.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.68% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.25% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.02% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.95% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 666 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 860 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 1,070 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,674 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 666 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 860 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 1,070 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,674 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.30% | 13.02% | 11.81% | |||||||||||||||||||||||||||||||||||||
| Annual Return [Percent] | 24.46% | 23.01% | 22.65% | (10.62%) | 16.60% | 11.17% | 27.75% | (15.58%) | 19.56% | 15.48% | ||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials Fund - Class M | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 3.50% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [1] | 0.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.68% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.50% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.02% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 1.20% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 468 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 718 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 987 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,754 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 468 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 718 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 987 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,754 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 19.77% | 13.27% | 11.78% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials Fund - Class C | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [2] | 1.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.68% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 1.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.02% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 1.70% | |||||||||||||||||||||||||||||||||||||||
| Expenses Deferred Charges [Text Block] | On Class C shares redeemed less than one year after purchase. | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 273 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 536 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 923 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,810 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 173 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 536 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 923 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,810 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 22.52% | 13.51% | 11.80% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials Fund - Class Z | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.55% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.02% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.57% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 58 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 183 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 318 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 714 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 58 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 183 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 318 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 714 | |||||||||||||||||||||||||||||||||||||||
| Annual Return, Inception Date | Oct. 02, 2018 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 24.91% | 14.82% | 11.99% | [3] | ||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Risk/Return [Heading] | Fund Summary Fund /Class: Fidelity Advisor® Industrials Fund /A, M, C, I, Z | |||||||||||||||||||||||||||||||||||||||
| Objective [Heading] | Investment Objective | |||||||||||||||||||||||||||||||||||||||
| Objective, Primary [Text Block] | Fidelity Advisor® Industrials Fund seeks capital appreciation. | |||||||||||||||||||||||||||||||||||||||
| Expense Heading [Optional Text] | Fee Table | |||||||||||||||||||||||||||||||||||||||
| Expense Narrative [Text Block] | The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 32 of the prospectus and in the sales charge waiver appendix to the prospectus. | |||||||||||||||||||||||||||||||||||||||
| Shareholder Fees Caption [Optional Text] | Shareholder fees | |||||||||||||||||||||||||||||||||||||||
| Operating Expenses Caption [Optional Text] | Annual Operating Expenses | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Heading] | Portfolio Turnover | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Text Block] | The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 34 % of the average value of its portfolio. | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover, Rate | 34.00% | |||||||||||||||||||||||||||||||||||||||
| Expenses Deferred Charges [Text Block] | Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively. | |||||||||||||||||||||||||||||||||||||||
| Expense Breakpoint Discounts [Text] | You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 32 of the prospectus | |||||||||||||||||||||||||||||||||||||||
| Expense Breakpoint, Minimum Investment Required [Amount] | $ 50,000 | |||||||||||||||||||||||||||||||||||||||
| Expense Example Narrative [Text Block] | This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares: | |||||||||||||||||||||||||||||||||||||||
| Strategy [Heading] | Principal Investment Strategies | |||||||||||||||||||||||||||||||||||||||
| Strategy Narrative [Text Block] | Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, distribution, supply, or sale of industrial products, services, or equipment. Industrial products, services and equipment, such as capital goods, construction services, machinery, commercial services, and transportation, are generally considered to be sensitive to the business cycle. These companies may include, for example, manufacturers of civil or military aerospace and defense equipment, building components, and home improvement products and equipment; civil engineering companies and large-scale contractors; companies that produce electrical components or equipment; manufacturers of industrial machinery and industrial components and products; manufacturers of agricultural machinery and equipment; providers of commercial printing services; companies providing business support services related to human capital management and office supplies, providers of commercial data processing and business outsourcing services, environmental and facilities maintenance; companies providing transportation services, including airlines, couriers, marine, road & rail, and transportation infrastructure. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. | |||||||||||||||||||||||||||||||||||||||
| Strategy Portfolio Concentration [Text] | Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, distribution, supply, or sale of industrial products, services, or equipment. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | Performance | |||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] | The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information. | |||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. | |||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | institutional.fidelity.com | |||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | Past performance (before and after taxes) is not an indication of future performance. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Year-by-Year Returns | |||||||||||||||||||||||||||||||||||||||
| Bar Chart Narrative [Text Block] | The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart Does Not Reflect Sales Loads [Text] | The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. | |||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | Year-to-Date Return | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 23.23% | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | Highest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2025 | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 20.09% | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | Lowest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2020 | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (28.79%) | |||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average Annual Returns | |||||||||||||||||||||||||||||||||||||||
| Performance Table Does Reflect Sales Loads | Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). | |||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Explanation after Tax Higher | Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Narrative | Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | After Taxes on Distributions | Fidelity Advisor Industrials Fund - Class I | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 24.31% | 12.70% | 11.09% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | After Taxes on Distributions | Fidelity Advisor Industrials Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 16.83% | 11.00% | 10.09% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | After Taxes on Distributions and Sales | Fidelity Advisor Industrials Fund - Class I | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions and Sale of Fund Shares | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.99% | 11.15% | 10.00% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | After Taxes on Distributions and Sales | Fidelity Advisor Industrials Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions and Sale of Fund Shares | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 10.58% | 9.76% | 9.15% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | F1511 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | MSCI U.S. IMI Industrials 25-50 Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 18.63% | 13.48% | 13.27% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | SP001 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | S&P 500® Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.88% | 14.42% | 14.82% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 5.75% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [4] | 0.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.67% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.25% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.02% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.94% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 665 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 857 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 1,065 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,663 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 665 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 857 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 1,065 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,663 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 31.53% | 6.36% | 7.66% | |||||||||||||||||||||||||||||||||||||
| Annual Return [Percent] | 39.55% | 5.34% | 10.68% | (7.95%) | (3.56%) | 32.16% | 25.70% | (3.78%) | 25.80% | (23.58%) | ||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology Fund - Class M | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 3.50% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [4] | 0.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.67% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.50% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.02% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 1.19% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 467 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 715 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 981 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,743 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 467 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 715 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 981 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,743 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 34.36% | 6.58% | 7.60% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology Fund - Class C | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [5] | 1.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.68% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 1.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.01% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 1.69% | |||||||||||||||||||||||||||||||||||||||
| Expenses Deferred Charges [Text Block] | On Class C shares redeemed less than one year after purchase. | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 272 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 533 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 918 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,799 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 172 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 533 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 918 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,799 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 37.50% | 6.82% | 7.66% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology Fund - Class I | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.68% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.01% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.69% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 70 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 221 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 384 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 859 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 70 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 221 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 384 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 859 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 39.93% | 7.91% | 8.59% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology Fund - Class Z | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.55% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.02% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.57% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 58 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 183 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 318 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 714 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 58 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 183 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 318 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 714 | |||||||||||||||||||||||||||||||||||||||
| Annual Return, Inception Date | Oct. 02, 2018 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 40.10% | 8.05% | 10.78% | [6] | ||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Risk/Return [Heading] | Fund Summary Fund /Class: Fidelity Advisor® Biotechnology Fund /A, M, C, I, Z | |||||||||||||||||||||||||||||||||||||||
| Objective [Heading] | Investment Objective | |||||||||||||||||||||||||||||||||||||||
| Objective, Primary [Text Block] | Fidelity Advisor® Biotechnology Fund seeks capital appreciation. | |||||||||||||||||||||||||||||||||||||||
| Expense Heading [Optional Text] | Fee Table | |||||||||||||||||||||||||||||||||||||||
| Expense Narrative [Text Block] | The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 32 of the prospectus and in the sales charge waiver appendix to the prospectus. | |||||||||||||||||||||||||||||||||||||||
| Shareholder Fees Caption [Optional Text] | Shareholder fees | |||||||||||||||||||||||||||||||||||||||
| Operating Expenses Caption [Optional Text] | Annual Operating Expenses | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Heading] | Portfolio Turnover | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Text Block] | The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 54 % of the average value of its portfolio. | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover, Rate | 54.00% | |||||||||||||||||||||||||||||||||||||||
| Expenses Deferred Charges [Text Block] | Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively. | |||||||||||||||||||||||||||||||||||||||
| Expense Breakpoint Discounts [Text] | You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 32 of the prospectus | |||||||||||||||||||||||||||||||||||||||
| Expense Breakpoint, Minimum Investment Required [Amount] | $ 50,000 | |||||||||||||||||||||||||||||||||||||||
| Expense Example Narrative [Text Block] | This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares: | |||||||||||||||||||||||||||||||||||||||
| Strategy [Heading] | Principal Investment Strategies | |||||||||||||||||||||||||||||||||||||||
| Strategy Narrative [Text Block] | Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, and distribution of various biotechnological products, services, and processes, and companies that benefit significantly from scientific and technological advances in biotechnology. These companies may include, for example, companies engaged in the research, development, manufacturing, or marketing of products based in whole or in part on genetic analysis and genetic engineering. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. | |||||||||||||||||||||||||||||||||||||||
| Strategy Portfolio Concentration [Text] | Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, and distribution of various biotechnological products, services, and processes, and companies that benefit significantly from scientific and technological advances in biotechnology. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | Performance | |||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] | The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information. | |||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. | |||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | institutional.fidelity.com | |||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | Past performance (before and after taxes) is not an indication of future performance. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Year-by-Year Returns | |||||||||||||||||||||||||||||||||||||||
| Bar Chart Narrative [Text Block] | The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart Does Not Reflect Sales Loads [Text] | The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. | |||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | Year-to-Date Return | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 21.50% | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | Highest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Jun. 30, 2020 | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 30.29% | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | Lowest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Mar. 31, 2016 | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (27.76%) | |||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average Annual Returns | |||||||||||||||||||||||||||||||||||||||
| Performance Table Does Reflect Sales Loads | Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). | |||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Explanation after Tax Higher | Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Narrative | Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | After Taxes on Distributions | Fidelity Advisor Biotechnology Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 30.89% | 4.83% | 6.38% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | After Taxes on Distributions and Sales | Fidelity Advisor Biotechnology Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions and Sale of Fund Shares | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 18.79% | 4.43% | 5.72% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | SP001 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | S&P 500® Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.88% | 14.42% | 14.82% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | F1501 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | MSCI U.S. IMI Biotechnology 25-50 Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 33.50% | 9.35% | 9.14% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 5.75% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [7] | 0.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.66% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.25% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.05% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.96% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 667 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 863 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 1,075 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,685 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 667 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 863 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 1,075 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,685 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.67% | 2.34% | 7.58% | |||||||||||||||||||||||||||||||||||||
| Annual Return [Percent] | 14.24% | 3.90% | 3.81% | (13.07%) | 11.19% | 21.08% | 27.89% | 7.34% | 24.09% | (10.33%) | ||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care Fund - Class M | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 3.50% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [7] | 0.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.66% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.50% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.05% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 1.21% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 469 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 721 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 992 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,765 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 469 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 721 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 992 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,765 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 9.96% | 2.56% | 7.56% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care Fund - Class C | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [8] | 1.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.66% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 1.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.05% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 1.71% | |||||||||||||||||||||||||||||||||||||||
| Expenses Deferred Charges [Text Block] | On Class C shares redeemed less than one year after purchase. | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 274 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 539 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 928 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,821 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 174 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 539 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 928 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,821 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 12.45% | 2.78% | 7.57% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care Fund - Class I | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.66% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.05% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.71% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 73 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 227 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 395 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 883 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 73 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 227 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 395 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 883 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.52% | 3.82% | 8.50% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care Fund - Class Z | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.54% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.05% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.59% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 60 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 189 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 329 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 738 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 60 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 189 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 329 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 738 | |||||||||||||||||||||||||||||||||||||||
| Annual Return, Inception Date | Oct. 02, 2018 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.66% | 3.95% | 6.96% | [9] | ||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Risk/Return [Heading] | Fund Summary Fund /Class: Fidelity Advisor® Health Care Fund /A, M, C, I, Z | |||||||||||||||||||||||||||||||||||||||
| Objective [Heading] | Investment Objective | |||||||||||||||||||||||||||||||||||||||
| Objective, Primary [Text Block] | Fidelity Advisor® Health Care Fund seeks capital appreciation. | |||||||||||||||||||||||||||||||||||||||
| Expense Heading [Optional Text] | Fee Table | |||||||||||||||||||||||||||||||||||||||
| Expense Narrative [Text Block] | The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 32 of the prospectus and in the sales charge waiver appendix to the prospectus. | |||||||||||||||||||||||||||||||||||||||
| Shareholder Fees Caption [Optional Text] | Shareholder fees | |||||||||||||||||||||||||||||||||||||||
| Operating Expenses Caption [Optional Text] | Annual Operating Expenses | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Heading] | Portfolio Turnover | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Text Block] | The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 74 % of the average value of its portfolio. | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover, Rate | 74.00% | |||||||||||||||||||||||||||||||||||||||
| Expenses Deferred Charges [Text Block] | Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively. | |||||||||||||||||||||||||||||||||||||||
| Expense Breakpoint Discounts [Text] | You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 32 of the prospectus | |||||||||||||||||||||||||||||||||||||||
| Expense Breakpoint, Minimum Investment Required [Amount] | $ 50,000 | |||||||||||||||||||||||||||||||||||||||
| Expense Example Narrative [Text Block] | This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares: | |||||||||||||||||||||||||||||||||||||||
| Strategy [Heading] | Principal Investment Strategies | |||||||||||||||||||||||||||||||||||||||
| Strategy Narrative [Text Block] | Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the design, manufacture, or sale of products or services used for or in connection with health care or medicine. These companies may include, for example, companies engaged in the research, development, manufacturing, or marketing of products based on biotechnology research; companies engaged in research, development, or production of pharmaceuticals, including veterinary drugs; manufacturers, distributors, and wholesalers of health care equipment, devices, and supplies including drug delivery systems and eye care products; and owners and operators of health care facilities, HMOs, and other managed plans. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. | |||||||||||||||||||||||||||||||||||||||
| Strategy Portfolio Concentration [Text] | Normally investing at least 80% of assets in securities of companies principally engaged in the design, manufacture, or sale of products or services used for or in connection with health care or medicine. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | Performance | |||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] | The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information. | |||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. | |||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | institutional.fidelity.com | |||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | Past performance (before and after taxes) is not an indication of future performance. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Year-by-Year Returns | |||||||||||||||||||||||||||||||||||||||
| Bar Chart Narrative [Text Block] | The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart Does Not Reflect Sales Loads [Text] | The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. | |||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | Year-to-Date Return | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 9.33% | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | Highest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Dec. 31, 2019 | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 21.25% | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | Lowest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Dec. 31, 2018 | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (15.00%) | |||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average Annual Returns | |||||||||||||||||||||||||||||||||||||||
| Performance Table Does Reflect Sales Loads | Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). | |||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Explanation after Tax Higher | Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Narrative | Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | After Taxes on Distributions | Fidelity Advisor Health Care Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 4.71% | 0.95% | 6.57% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | After Taxes on Distributions and Sales | Fidelity Advisor Health Care Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions and Sale of Fund Shares | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 6.72% | 1.75% | 6.07% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | SP001 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | S&P 500® Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.88% | 14.42% | 14.82% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | F1513 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | MSCI U.S. IMI Health Care 25-50 Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.54% | 6.79% | 9.72% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 5.75% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [10] | 0.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.65% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.25% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.01% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.91% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 663 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 848 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 1,050 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,630 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 663 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 848 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 1,050 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,630 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 36.54% | 28.56% | 29.09% | |||||||||||||||||||||||||||||||||||||
| Annual Return [Percent] | 44.87% | 43.72% | 74.91% | (35.05%) | 57.52% | 43.62% | 63.75% | (12.49%) | 34.24% | 32.42% | ||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors Fund - Class M | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 3.50% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [10] | 0.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.65% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.50% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.01% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 1.16% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 464 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 706 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 966 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,710 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 464 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 706 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 966 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,710 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 39.46% | 28.85% | 29.02% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors Fund - Class C | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | [11] | 1.00% | ||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.65% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 1.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.01% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 1.66% | |||||||||||||||||||||||||||||||||||||||
| Expenses Deferred Charges [Text Block] | On Class C shares redeemed less than one year after purchase. | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 269 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 523 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 902 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 1,766 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 169 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 523 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 902 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 1,766 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 42.78% | 29.12% | 29.06% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors Fund - Class I | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.65% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.01% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.66% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 67 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 211 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 368 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 822 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 67 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 211 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 368 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 822 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 45.24% | 30.43% | 30.21% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors Fund - Class Z | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Maximum Cumulative Sales Charge (as a percentage of Offering Price) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Maximum Deferred Sales Charge (as a percentage) | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Management Fees (as a percentage of Assets) | 0.53% | |||||||||||||||||||||||||||||||||||||||
| Distribution and Service (12b-1) Fees | 0.00% | |||||||||||||||||||||||||||||||||||||||
| Other Expenses (as a percentage of Assets): | 0.01% | |||||||||||||||||||||||||||||||||||||||
| Expenses (as a percentage of Assets) | 0.54% | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 1 Year | $ 55 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 3 Years | 173 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 5 Years | 302 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, with Redemption, 10 Years | 677 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 1 Year | 55 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 3 Years | 173 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 5 Years | 302 | |||||||||||||||||||||||||||||||||||||||
| Expense Example, No Redemption, 10 Years | $ 677 | |||||||||||||||||||||||||||||||||||||||
| Annual Return, Inception Date | Oct. 02, 2018 | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return Before Taxes | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 45.41% | 30.58% | 31.89% | [12] | ||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Risk/Return [Heading] | Fund Summary Fund /Class: Fidelity Advisor® Semiconductors Fund /A, M, C, I, Z | |||||||||||||||||||||||||||||||||||||||
| Objective [Heading] | Investment Objective | |||||||||||||||||||||||||||||||||||||||
| Objective, Primary [Text Block] | Fidelity Advisor® Semiconductors Fund seeks capital appreciation. | |||||||||||||||||||||||||||||||||||||||
| Expense Heading [Optional Text] | Fee Table | |||||||||||||||||||||||||||||||||||||||
| Expense Narrative [Text Block] | The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 32 of the prospectus and in the sales charge waiver appendix to the prospectus. | |||||||||||||||||||||||||||||||||||||||
| Shareholder Fees Caption [Optional Text] | Shareholder fees | |||||||||||||||||||||||||||||||||||||||
| Operating Expenses Caption [Optional Text] | Annual Operating Expenses | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Heading] | Portfolio Turnover | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover [Text Block] | The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 99 % of the average value of its portfolio. | |||||||||||||||||||||||||||||||||||||||
| Portfolio Turnover, Rate | 99.00% | |||||||||||||||||||||||||||||||||||||||
| Expenses Deferred Charges [Text Block] | Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively. | |||||||||||||||||||||||||||||||||||||||
| Expense Breakpoint Discounts [Text] | You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 32 of the prospectus | |||||||||||||||||||||||||||||||||||||||
| Expense Breakpoint, Minimum Investment Required [Amount] | $ 50,000 | |||||||||||||||||||||||||||||||||||||||
| Expense Example Narrative [Text Block] | This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares: | |||||||||||||||||||||||||||||||||||||||
| Strategy [Heading] | Principal Investment Strategies | |||||||||||||||||||||||||||||||||||||||
| Strategy Narrative [Text Block] | Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the design, manufacture, or sale of semiconductors and semiconductor equipment. These companies may include, for example, manufacturers of semiconductor equipment and related products. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Also investing primarily in companies engaged in the design, manufacture, or sale of electronic components (semiconductors, connectors, printed circuit boards and other components); equipment vendors to electronic component manufacturers; electronic component distributors; and electronic instruments and electronic systems vendors. Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. | |||||||||||||||||||||||||||||||||||||||
| Strategy Portfolio Concentration [Text] | Normally investing at least 80% of assets in securities of companies principally engaged in the design, manufacture, or sale of semiconductors and semiconductor equipment. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart and Performance Table [Heading] | Performance | |||||||||||||||||||||||||||||||||||||||
| Performance Narrative [Text Block] | The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information. | |||||||||||||||||||||||||||||||||||||||
| Performance Information Illustrates Variability of Returns [Text] | The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. | |||||||||||||||||||||||||||||||||||||||
| Performance Availability Website Address [Text] | institutional.fidelity.com | |||||||||||||||||||||||||||||||||||||||
| Performance Past Does Not Indicate Future [Text] | Past performance (before and after taxes) is not an indication of future performance. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart [Heading] | Year-by-Year Returns | |||||||||||||||||||||||||||||||||||||||
| Bar Chart Narrative [Text Block] | The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. | |||||||||||||||||||||||||||||||||||||||
| Bar Chart Does Not Reflect Sales Loads [Text] | The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. | |||||||||||||||||||||||||||||||||||||||
| Year to Date Return, Label [Optional Text] | Year-to-Date Return | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 | |||||||||||||||||||||||||||||||||||||||
| Bar Chart, Year to Date Return | 80.24% | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Label [Optional Text] | Highest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return, Date | Mar. 31, 2023 | |||||||||||||||||||||||||||||||||||||||
| Highest Quarterly Return | 38.96% | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Label [Optional Text] | Lowest Quarter Return | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return, Date | Jun. 30, 2022 | |||||||||||||||||||||||||||||||||||||||
| Lowest Quarterly Return | (28.90%) | |||||||||||||||||||||||||||||||||||||||
| Performance Table Heading | Average Annual Returns | |||||||||||||||||||||||||||||||||||||||
| Performance Table Does Reflect Sales Loads | Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Uses Highest Federal Rate | After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Not Relevant to Tax Deferred | The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). | |||||||||||||||||||||||||||||||||||||||
| Performance Table One Class of after Tax Shown [Text] | After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Explanation after Tax Higher | Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| Performance Table Narrative | Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. | |||||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | After Taxes on Distributions | Fidelity Advisor Semiconductors Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 34.28% | 27.04% | 27.20% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | After Taxes on Distributions and Sales | Fidelity Advisor Semiconductors Fund - Class A | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | Return After Taxes on Distributions and Sale of Fund Shares | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 22.98% | 23.32% | 24.71% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | SP001 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | S&P 500® Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.88% | 14.42% | 14.82% | |||||||||||||||||||||||||||||||||||||
| FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | F1508 | ||||||||||||||||||||||||||||||||||||||||
| Prospectus Line Items | ||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Label [Optional Text] | MSCI U.S. IMI Semiconductors & Semiconductor Equipment 25-50 Index | |||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 45.93% | 30.17% | 29.92% | |||||||||||||||||||||||||||||||||||||
| Document Type | 485BPOS | |||||||||||||||||||||||||||||||||||||||
| Registrant Name | Fidelity Advisor Series VII | |||||||||||||||||||||||||||||||||||||||
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