v3.25.2
Shareholder Report
 6 Months Ended
Jun. 30, 2025
USD ($)
shares
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Fidelity Contrafund
Entity Central Index Key 0000024238
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2025
Fidelity Series Opportunistic Insights Fund  
Shareholder Report [Line Items]  
Fund Name Fidelity® Series Opportunistic Insights Fund
Class Name Fidelity® Series Opportunistic Insights Fund
Trading Symbol FVWSX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Series Opportunistic Insights Fund for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544.
Additional Information Phone Number 1-800-544-8544
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Series Opportunistic Insights Fund 
$ 0 A
0.00%B
  
A Amount represents less than $.50
B Amount represents less than 0.005%
 
Expenses Paid, Amount $ 0
Expense Ratio, Percent 0.00%
Net Assets $ 12,091,006,718
Holdings Count | shares 343
Investment Company Portfolio Turnover 28.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$12,091,006,718
  
Number of Holdings
343
  
Portfolio Turnover
28%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Information Technology 24.2   Communication Services 24.1   Financials 19.2   Industrials 10.3   Consumer Discretionary 9.7   Health Care 6.9   Consumer Staples 1.7   Materials 1.2   Utilities 1.1   Energy 0.6   Real Estate 0.1     Common Stocks 97.6 Preferred Stocks 1.5 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.9 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 97.6                       Preferred Stocks - 1.5                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 0.9   United States 93.1 Canada 2.7 Brazil 0.6 Korea (South) 0.5 Taiwan 0.4 United Kingdom 0.4 China 0.4 Japan 0.3 Israel 0.3 Others 1.3 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 93.1                       Canada - 2.7                               Brazil - 0.6                               Korea (South) - 0.5                        Taiwan - 0.4                               United Kingdom - 0.4                       China - 0.4                                Japan - 0.3                                Israel - 0.3                               Others - 1.3                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 15.4   NVIDIA Corp 10.3   Berkshire Hathaway Inc Class A 6.1   Amazon.com Inc 5.2   Microsoft Corp 4.5   Netflix Inc 4.1   Visa Inc Class A 2.2   Amphenol Corp Class A 2.2   JPMorgan Chase & Co 2.0   GE Vernova Inc 1.7     53.7  
Fidelity Contrafund K6  
Shareholder Report [Line Items]  
Fund Name Fidelity® Contrafund® K6
Class Name Fidelity® Contrafund® K6
Trading Symbol FLCNX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Contrafund® K6 for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-835-5092 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-835-5092
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Contrafund® K6 
$ 24 
0.45%
  
Expenses Paid, Amount $ 24
Expense Ratio, Percent 0.45%
Net Assets $ 35,942,553,767
Holdings Count | shares 353
Investment Company Portfolio Turnover 20.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$35,942,553,767
  
Number of Holdings
353
  
Portfolio Turnover
20%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Information Technology 25.8   Communication Services 25.7   Financials 18.3   Consumer Discretionary 9.6   Industrials 7.7   Health Care 6.0   Consumer Staples 2.0   Materials 1.3   Utilities 1.2   Energy 0.6   Real Estate 0.1     Common Stocks 97.1 Preferred Stocks 1.2 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 1.7 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 97.1                       Preferred Stocks - 1.2                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 1.7   United States 93.6 Canada 2.4 Brazil 0.5 Korea (South) 0.5 Taiwan 0.5 United Kingdom 0.3 Japan 0.3 China 0.3 Congo Democratic Republic Of 0.3 Others 1.3 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 93.6                       Canada - 2.4                               Brazil - 0.5                               Korea (South) - 0.5                        Taiwan - 0.5                               United Kingdom - 0.3                       Japan - 0.3                                China - 0.3                                Congo Democratic Republic Of - 0.3         Others - 1.3                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 17.5   NVIDIA Corp 10.6   Berkshire Hathaway Inc Class A 8.0   Amazon.com Inc 5.8   Microsoft Corp 5.2   Netflix Inc 3.5   Amphenol Corp Class A 2.5   Apple Inc 1.9   Alphabet Inc Class A 1.9   Visa Inc Class A 1.9     58.8  
Fidelity Contrafund  
Shareholder Report [Line Items]  
Fund Name Fidelity® Contrafund®
Class Name Fidelity® Contrafund®
Trading Symbol FCNTX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Contrafund® for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-544-8544
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Contrafund® 
$ 39 
0.75%
  
Expenses Paid, Amount $ 39
Expense Ratio, Percent 0.75%
Net Assets $ 166,631,799,894
Holdings Count | shares 360
Investment Company Portfolio Turnover 20.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$166,631,799,894
  
Number of Holdings
360
  
Portfolio Turnover
20%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Communication Services 26.1   Information Technology 23.8   Financials 18.4   Consumer Discretionary 9.9   Industrials 8.1   Health Care 6.6   Consumer Staples 1.9   Materials 1.2   Utilities 1.2   Energy 0.8   Real Estate 0.1     Common Stocks 96.3 Preferred Stocks 1.8 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 1.9 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 96.3                       Preferred Stocks - 1.8                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 1.9   United States 93.7 Canada 2.2 Brazil 0.5 Taiwan 0.4 Korea (South) 0.4 United Kingdom 0.4 China 0.4 Japan 0.3 Switzerland 0.3 Others 1.4 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 93.7                       Canada - 2.2                               Brazil - 0.5                               Taiwan - 0.4                               Korea (South) - 0.4                        United Kingdom - 0.4                       China - 0.4                                Japan - 0.3                                Switzerland - 0.3                          Others - 1.4                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 18.2   NVIDIA Corp 9.0   Berkshire Hathaway Inc Class A 8.3   Amazon.com Inc 6.3   Microsoft Corp 5.3   Netflix Inc 3.2   Amphenol Corp Class A 2.3   Apple Inc 2.2   Eli Lilly & Co 2.0   Alphabet Inc Class A 1.9     58.7  
Fidelity Contrafund - Class K  
Shareholder Report [Line Items]  
Fund Name Fidelity® Contrafund®
Class Name Fidelity® Contrafund® Class K
Trading Symbol FCNKX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Contrafund® for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-835-5092 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-835-5092
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class K 
$ 36 
0.68%
  
Expenses Paid, Amount $ 36
Expense Ratio, Percent 0.68%
Net Assets $ 166,631,799,894
Holdings Count | shares 360
Investment Company Portfolio Turnover 20.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$166,631,799,894
  
Number of Holdings
360
  
Portfolio Turnover
20%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Communication Services 26.1   Information Technology 23.8   Financials 18.4   Consumer Discretionary 9.9   Industrials 8.1   Health Care 6.6   Consumer Staples 1.9   Materials 1.2   Utilities 1.2   Energy 0.8   Real Estate 0.1     Common Stocks 96.3 Preferred Stocks 1.8 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 1.9 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 96.3                       Preferred Stocks - 1.8                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 1.9   United States 93.7 Canada 2.2 Brazil 0.5 Taiwan 0.4 Korea (South) 0.4 United Kingdom 0.4 China 0.4 Japan 0.3 Switzerland 0.3 Others 1.4 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 93.7                       Canada - 2.2                               Brazil - 0.5                               Taiwan - 0.4                               Korea (South) - 0.4                        United Kingdom - 0.4                       China - 0.4                                Japan - 0.3                                Switzerland - 0.3                          Others - 1.4                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 18.2   NVIDIA Corp 9.0   Berkshire Hathaway Inc Class A 8.3   Amazon.com Inc 6.3   Microsoft Corp 5.3   Netflix Inc 3.2   Amphenol Corp Class A 2.3   Apple Inc 2.2   Eli Lilly & Co 2.0   Alphabet Inc Class A 1.9     58.7  
Fidelity Advisor New Insights Fund - Class Z  
Shareholder Report [Line Items]  
Fund Name Fidelity Advisor® New Insights Fund
Class Name Fidelity Advisor® New Insights Fund Class Z
Trading Symbol FZANX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity Advisor® New Insights Fund for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class Z 
$ 38 
0.72%
  
Expenses Paid, Amount $ 38
Expense Ratio, Percent 0.72%
Net Assets $ 23,178,940,335
Holdings Count | shares 408
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$23,178,940,335
  
Number of Holdings
408
  
Portfolio Turnover
23%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Information Technology 24.5   Communication Services 23.4   Financials 15.2   Industrials 13.0   Consumer Discretionary 10.3   Health Care 7.3   Materials 1.9   Utilities 1.5   Consumer Staples 1.2   Energy 1.1   Real Estate 0.2     Common Stocks 97.0 Preferred Stocks 2.6 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 97.0                       Preferred Stocks - 2.6                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 0.4   United States 91.8 Canada 2.3 Taiwan 0.9 Netherlands 0.7 Brazil 0.6 China 0.5 United Kingdom 0.5 Japan 0.5 Italy 0.4 Others 1.8 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 91.8                       Canada - 2.3                               Taiwan - 0.9                               Netherlands - 0.7                          Brazil - 0.6                               China - 0.5                                United Kingdom - 0.5                       Japan - 0.5                                Italy - 0.4                                Others - 1.8                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 13.5   NVIDIA Corp 9.2   Microsoft Corp 5.7   Amazon.com Inc 5.3   Berkshire Hathaway Inc Class A 5.0   Alphabet Inc Class A 4.7   Netflix Inc 3.6   Space Exploration Technologies Corp 2.2   Eli Lilly & Co 1.6   Apple Inc 1.5     52.3  
Fidelity Advisor New Insights Fund - Class M  
Shareholder Report [Line Items]  
Fund Name Fidelity Advisor® New Insights Fund
Class Name Fidelity Advisor® New Insights Fund Class M
Trading Symbol FNITX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity Advisor® New Insights Fund for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class M 
$ 70 
1.33%
  
Expenses Paid, Amount $ 70
Expense Ratio, Percent 1.33%
Net Assets $ 23,178,940,335
Holdings Count | shares 408
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$23,178,940,335
  
Number of Holdings
408
  
Portfolio Turnover
23%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Information Technology 24.5   Communication Services 23.4   Financials 15.2   Industrials 13.0   Consumer Discretionary 10.3   Health Care 7.3   Materials 1.9   Utilities 1.5   Consumer Staples 1.2   Energy 1.1   Real Estate 0.2     Common Stocks 97.0 Preferred Stocks 2.6 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 97.0                       Preferred Stocks - 2.6                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 0.4   United States 91.8 Canada 2.3 Taiwan 0.9 Netherlands 0.7 Brazil 0.6 China 0.5 United Kingdom 0.5 Japan 0.5 Italy 0.4 Others 1.8 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 91.8                       Canada - 2.3                               Taiwan - 0.9                               Netherlands - 0.7                          Brazil - 0.6                               China - 0.5                                United Kingdom - 0.5                       Japan - 0.5                                Italy - 0.4                                Others - 1.8                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 13.5   NVIDIA Corp 9.2   Microsoft Corp 5.7   Amazon.com Inc 5.3   Berkshire Hathaway Inc Class A 5.0   Alphabet Inc Class A 4.7   Netflix Inc 3.6   Space Exploration Technologies Corp 2.2   Eli Lilly & Co 1.6   Apple Inc 1.5     52.3  
Fidelity Advisor New Insights Fund - Class I  
Shareholder Report [Line Items]  
Fund Name Fidelity Advisor® New Insights Fund
Class Name Fidelity Advisor® New Insights Fund Class I
Trading Symbol FINSX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity Advisor® New Insights Fund for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class I 
$ 44 
0.83%
  
Expenses Paid, Amount $ 44
Expense Ratio, Percent 0.83%
Net Assets $ 23,178,940,335
Holdings Count | shares 408
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$23,178,940,335
  
Number of Holdings
408
  
Portfolio Turnover
23%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Information Technology 24.5   Communication Services 23.4   Financials 15.2   Industrials 13.0   Consumer Discretionary 10.3   Health Care 7.3   Materials 1.9   Utilities 1.5   Consumer Staples 1.2   Energy 1.1   Real Estate 0.2     Common Stocks 97.0 Preferred Stocks 2.6 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 97.0                       Preferred Stocks - 2.6                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 0.4   United States 91.8 Canada 2.3 Taiwan 0.9 Netherlands 0.7 Brazil 0.6 China 0.5 United Kingdom 0.5 Japan 0.5 Italy 0.4 Others 1.8 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 91.8                       Canada - 2.3                               Taiwan - 0.9                               Netherlands - 0.7                          Brazil - 0.6                               China - 0.5                                United Kingdom - 0.5                       Japan - 0.5                                Italy - 0.4                                Others - 1.8                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 13.5   NVIDIA Corp 9.2   Microsoft Corp 5.7   Amazon.com Inc 5.3   Berkshire Hathaway Inc Class A 5.0   Alphabet Inc Class A 4.7   Netflix Inc 3.6   Space Exploration Technologies Corp 2.2   Eli Lilly & Co 1.6   Apple Inc 1.5     52.3  
Fidelity Advisor New Insights Fund - Class C  
Shareholder Report [Line Items]  
Fund Name Fidelity Advisor® New Insights Fund
Class Name Fidelity Advisor® New Insights Fund Class C
Trading Symbol FNICX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity Advisor® New Insights Fund for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class C 
$ 96 
1.84%
  
Expenses Paid, Amount $ 96
Expense Ratio, Percent 1.84%
Net Assets $ 23,178,940,335
Holdings Count | shares 408
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$23,178,940,335
  
Number of Holdings
408
  
Portfolio Turnover
23%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Information Technology 24.5   Communication Services 23.4   Financials 15.2   Industrials 13.0   Consumer Discretionary 10.3   Health Care 7.3   Materials 1.9   Utilities 1.5   Consumer Staples 1.2   Energy 1.1   Real Estate 0.2     Common Stocks 97.0 Preferred Stocks 2.6 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 97.0                       Preferred Stocks - 2.6                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 0.4   United States 91.8 Canada 2.3 Taiwan 0.9 Netherlands 0.7 Brazil 0.6 China 0.5 United Kingdom 0.5 Japan 0.5 Italy 0.4 Others 1.8 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 91.8                       Canada - 2.3                               Taiwan - 0.9                               Netherlands - 0.7                          Brazil - 0.6                               China - 0.5                                United Kingdom - 0.5                       Japan - 0.5                                Italy - 0.4                                Others - 1.8                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 13.5   NVIDIA Corp 9.2   Microsoft Corp 5.7   Amazon.com Inc 5.3   Berkshire Hathaway Inc Class A 5.0   Alphabet Inc Class A 4.7   Netflix Inc 3.6   Space Exploration Technologies Corp 2.2   Eli Lilly & Co 1.6   Apple Inc 1.5     52.3  
Fidelity Advisor New Insights Fund - Class A  
Shareholder Report [Line Items]  
Fund Name Fidelity Advisor® New Insights Fund
Class Name Fidelity Advisor® New Insights Fund Class A
Trading Symbol FNIAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity Advisor® New Insights Fund for the period January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class A 
$ 57 
1.08%
  
Expenses Paid, Amount $ 57
Expense Ratio, Percent 1.08%
Net Assets $ 23,178,940,335
Holdings Count | shares 408
Investment Company Portfolio Turnover 23.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2025)
 
KEY FACTS 
  
  
Fund Size
$23,178,940,335
  
Number of Holdings
408
  
Portfolio Turnover
23%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Information Technology 24.5   Communication Services 23.4   Financials 15.2   Industrials 13.0   Consumer Discretionary 10.3   Health Care 7.3   Materials 1.9   Utilities 1.5   Consumer Staples 1.2   Energy 1.1   Real Estate 0.2     Common Stocks 97.0 Preferred Stocks 2.6 Preferred Securities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 97.0                       Preferred Stocks - 2.6                     Preferred Securities - 0.0                 Short-Term Investments and Net Other Assets (Liabilities) - 0.4   United States 91.8 Canada 2.3 Taiwan 0.9 Netherlands 0.7 Brazil 0.6 China 0.5 United Kingdom 0.5 Japan 0.5 Italy 0.4 Others 1.8 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 91.8                       Canada - 2.3                               Taiwan - 0.9                               Netherlands - 0.7                          Brazil - 0.6                               China - 0.5                                United Kingdom - 0.5                       Japan - 0.5                                Italy - 0.4                                Others - 1.8                                  
Largest Holdings [Text Block] TOP HOLDINGS (% of Fund's net assets)     Meta Platforms Inc Class A 13.5   NVIDIA Corp 9.2   Microsoft Corp 5.7   Amazon.com Inc 5.3   Berkshire Hathaway Inc Class A 5.0   Alphabet Inc Class A 4.7   Netflix Inc 3.6   Space Exploration Technologies Corp 2.2   Eli Lilly & Co 1.6   Apple Inc 1.5     52.3