Shareholder Report |
6 Months Ended |
|---|---|
|
Jun. 30, 2025
USD ($)
Holding
| |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | T. ROWE PRICE INDEX TRUST, INC. |
| Entity Central Index Key | 0000858581 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Jun. 30, 2025 |
| C000005458 | |
| Shareholder Report [Line Items] | |
| Fund Name | Extended Equity Market Index Fund |
| Trading Symbol | PEXMX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Extended Equity Market Index Fund (the "fund") for the period of January 1, 2025 to June 30, 2025. You can find the fund’s prospectus, financial information on Form N‑CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information atwww.troweprice.com/prospectus. You can also request this information without charge by contacting T. Rowe Price at 1‑800‑638‑5660 or info@troweprice.com or contacting your intermediary. |
| Shareholder Report Annual or Semi-Annual | Semi-Annual Shareholder Report |
| Additional Information [Text Block] | You can find the fund’s prospectus, financial information on Form N‑CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information atwww.troweprice.com/prospectus. You can also request this information without charge by contacting T. Rowe Price at 1‑800‑638‑5660 or info@troweprice.com or contacting your intermediary. |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | 1‑800‑638‑5660 |
| Additional Information Email | <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 17.3333px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">info@troweprice.com</span> |
| Additional Information Website | www.troweprice.com/prospectus |
| Expenses [Text Block] | |
| Expenses Paid, Amount | $ 12 |
| Expense Ratio, Percent | 0.24% |
| Updated Performance Information Location [Text Block] | If you invest directly with T. Rowe Price, you can elect to receive future shareholder reports or other important documents through electronic delivery by enrolling at www.troweprice.com/paperless. If you invest through a financial intermediary such as an investment advisor, a bank, retirement plan sponsor or a brokerage firm, please contact that organization and ask if it can provide electronic delivery. Visit www.troweprice.com/en/us/market-data-disclosures for additional legal notices & disclaimers. |
| AssetsNet | $ 986,469,000 |
| Holdings Count | Holding | 1,595 |
| InvestmentCompanyPortfolioTurnover | 4.10% |
| Additional Fund Statistics [Text Block] | |
| Additional Fund Statistics Significance or Limits [Text Block] | |
| Holdings [Text Block] | |
| Largest Holdings [Text Block] | |
| Material Fund Change [Text Block] | |
| Updated Prospectus Web Address | www.troweprice.com/paperless |