v3.26.3
Shareholder Report
 6 Months Ended
Aug. 31, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name T. ROWE PRICE TAX-FREE SHORT-INTERMEDIATE FUND, INC.
Entity Central Index Key 0000730200
Entity Investment Company Type N-1A
Document Period End Date Aug. 31, 2026
Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
C000005562  
Shareholder Report [Line Items]  
Fund Name Short-Intermediate Municipal Bond Fund
Class Name Investor Class
Trading Symbol PRFSX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Short-Intermediate Municipal Bond Fund (the "fund") for the period of March 1, 2026 to August 31, 2026.
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]

What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)

Table Summary
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Short-Intermediate Municipal Bond Fund - Investor Class
$23
0.46%
Expenses Paid, Amount $ 23
Expense Ratio, Percent 0.46%
AssetsNet $ 1,177,997,000
Holdings Count | Holding 536
InvestmentCompanyPortfolioTurnover 27.00%
Additional Fund Statistics [Text Block]

What are some fund statistics?

Fund Statistics

Table Summary
Total Net Assets (000s)
$1,177,997
Number of Portfolio Holdings
536
Holdings [Text Block]

State Allocation (as a % of Net Assets)

Table Summary
Texas
12.4%
New York
10.5
Alabama
8.1
Puerto Rico
6.0
Virginia
5.1
Colorado
5.0
Illinois
4.5
California
3.9
Florida
3.2
Other
41.3

Industry Allocation (as a % of Net Assets)

Table Summary
Health Care
19.9%
Transportation
16.8
Housing
14.7
General Obligations - State
7.2
Education
5.8
Special Tax
5.3
Industrial & Pollution Control
5.3
General Obligations - Local
4.9
Electric
3.4
Other
16.7
Material Fund Change [Text Block]
Updated Prospectus Web Address www.troweprice.com/paperless
C000117196  
Shareholder Report [Line Items]  
Fund Name Short-Intermediate Municipal Bond Fund
Class Name Advisor Class
Trading Symbol PATIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Short-Intermediate Municipal Bond Fund (the "fund") for the period of March 1, 2026 to August 31, 2026.
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]

What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)

Table Summary
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Short-Intermediate Municipal Bond Fund - Advisor Class
$40
0.80%
Expenses Paid, Amount $ 40
Expense Ratio, Percent 0.80%
AssetsNet $ 1,177,997,000
Holdings Count | Holding 536
InvestmentCompanyPortfolioTurnover 27.00%
Additional Fund Statistics [Text Block]

What are some fund statistics?

Fund Statistics

Table Summary
Total Net Assets (000s)
$1,177,997
Number of Portfolio Holdings
536
Holdings [Text Block]

State Allocation (as a % of Net Assets)

Table Summary
Texas
12.4%
New York
10.5
Alabama
8.1
Puerto Rico
6.0
Virginia
5.1
Colorado
5.0
Illinois
4.5
California
3.9
Florida
3.2
Other
41.3

Industry Allocation (as a % of Net Assets)

Table Summary
Health Care
19.9%
Transportation
16.8
Housing
14.7
General Obligations - State
7.2
Education
5.8
Special Tax
5.3
Industrial & Pollution Control
5.3
General Obligations - Local
4.9
Electric
3.4
Other
16.7
Material Fund Change [Text Block]
Updated Prospectus Web Address www.troweprice.com/paperless
C000177206  
Shareholder Report [Line Items]  
Fund Name Short-Intermediate Municipal Bond Fund
Class Name I Class
Trading Symbol TTSIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about Short-Intermediate Municipal Bond Fund (the "fund") for the period of March 1, 2026 to August 31, 2026.
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]

What were the fund costs for the last six months? (based on a hypothetical $10,000 investment)

Table Summary
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Short-Intermediate Municipal Bond Fund - I Class
$13
0.25%
Expenses Paid, Amount $ 13
Expense Ratio, Percent 0.25%
AssetsNet $ 1,177,997,000
Holdings Count | Holding 536
InvestmentCompanyPortfolioTurnover 27.00%
Additional Fund Statistics [Text Block]

What are some fund statistics?

Fund Statistics

Table Summary
Total Net Assets (000s)
$1,177,997
Number of Portfolio Holdings
536
Holdings [Text Block]

State Allocation (as a % of Net Assets)

Table Summary
Texas
12.4%
New York
10.5
Alabama
8.1
Puerto Rico
6.0
Virginia
5.1
Colorado
5.0
Illinois
4.5
California
3.9
Florida
3.2
Other
41.3

Industry Allocation (as a % of Net Assets)

Table Summary
Health Care
19.9%
Transportation
16.8
Housing
14.7
General Obligations - State
7.2
Education
5.8
Special Tax
5.3
Industrial & Pollution Control
5.3
General Obligations - Local
4.9
Electric
3.4
Other
16.7
Material Fund Change [Text Block]
Updated Prospectus Web Address www.troweprice.com/paperless