| Form N-CSR Cover | 6 Months Ended |
| Jun. 30, 2024 | |
| 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, 2024 |
| Shareholder Report | 6 Months Ended |
| Jun. 30, 2024 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, 2024 |
| C000005459 | |
| Shareholder Report [Line Items] | |
| Fund Name | Total Equity Market Index Fund |
| Trading Symbol | POMIX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Total Equity Market Index Fund (the "fund") for the period of January 1, 2024 to June 30, 2024. 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 at www.troweprice.com/prospectus info troweprice.com |
| 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 at www.troweprice.com/prospectus info troweprice.com |
| Material Fund Change Notice [Text Block] | |
| Additional Information Phone Number | 1‑800‑638‑5660 |
| Additional Information Email | info@troweprice.com</span>" id="sjs-B19"><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;">info@troweprice.com</span> |
| Additional Information Website | www.troweprice.com/prospectus</span>" id="sjs-B20"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 700; grid-area: auto; line-height: 17.3333px; margin: 0px; overflow: visible; text-align: justify;">www.troweprice.com/prospectus</span> |
| Expenses [Text Block] | What were the fund costs for the last six months? Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Total Equity Market Index Fund $10 0.18% |
| Expenses Paid, Amount | $ 10 |
| Expense Ratio, Percent | 0.18% |
| 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 |
| AssetsNet | $ 2,549,071,000 |
| Holdings Count | Holding | 1,197 |
| InvestmentCompanyPortfolioTurnover | 2.80% |
| Additional Fund Statistics [Text Block] | What are some fund statistics? Fund Statistics Total Net Assets (000s) $2,549,071 Number of Portfolio Holdings 1,197 |
| Additional Fund Statistics Significance or Limits [Text Block] | Portfolio Turnover Rate 2.8% |
| Holdings [Text Block] | Sector Allocation Information Technology 30.3 % Financials 13.0 Health Care 11.8 Consumer Discretionary 10.2 Industrials & Business Services 9.4 Communication Services 8.6 Consumer Staples 5.3 Energy 3.8 Materials 2.5 Other 5.1 |
| Largest Holdings [Text Block] | Top Ten Holdings Microsoft 6.3 % NVIDIA 5.8 Apple 5.8 Alphabet 3.8 Amazon.com 3.4 Meta Platforms 2.1 Berkshire Hathaway 1.4 Eli Lilly 1.4 Broadcom 1.3 JPMorgan Chase 1.1 |
| Material Fund Change [Text Block] | |
| Updated Prospectus Web Address | www.troweprice.com/paperless</span>" id="sjs-B33"><span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 10.6667px; font-weight: 400; grid-area: auto; line-height: 13.8667px; margin: 0px; overflow: visible; text-align: justify;">www.troweprice.com/paperless</span> |
| Shareholder Report, Holdings (Details) - C000005459 | Jun. 30, 2024 |
| Microsoft | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.30% |
| NVIDIA | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Apple | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Alphabet | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Amazon.com | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Meta Platforms | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.10% |
| Berkshire Hathaway | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| Eli Lilly | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| Broadcom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| JPMorgan Chase | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Information Technology | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.30% |
| Financials | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Health Care | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.80% |
| Consumer Discretionary | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Industrials & Business Services | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.40% |
| Communication Services | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Consumer Staples | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Energy | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Materials | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.50% |
