v3.25.2
Shareholder Report
6 Months Ended
Apr. 30, 2025
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Short Duration Inflation-Protected Income Portfolio
Entity Central Index Key 0001928846
Entity Investment Company Type N-1A
Document Period End Date Apr. 30, 2025
C000237224  
Shareholder Report [Line Items]  
Fund Name Short Duration Inflation-Protected Income Portfolio
No Trading Symbol [Flag] true
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about the Short Duration Inflation-Protected Income Portfolio (the "Fund") for the period of November 1, 2024 to April 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 www.eatonvance.com/open-end-mutual-fund-documents.php and selecting Eaton Vance Short Duration Inflation-Protected Income Fund. You can also request this information by contacting us at 1-800-262-1122.
Additional Information Phone Number 1-800-262-1122
Additional Information Website <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: 16px; margin: 0px; overflow: visible; text-align: left; white-space-collapse: preserve-breaks;">www.eatonvance.com/open-end-mutual-fund-documents.php</span>
Expenses [Text Block]

What were the Fund costs for the last six months?

(based on a hypothetical $10,000 investment)

Fund Name
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Short Duration Inflation-Protected Income Portfolio
$26
0.52%Footnote Reference1
Footnote Description
Footnote1
Annualized
Expenses Paid, Amount $ 26
Expense Ratio, Percent 0.52% [1]
AssetsNet $ 398,976,610
Holdings Count | Holding 37
InvestmentCompanyPortfolioTurnover 28.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

Total Net Assets
$398,976,610
# of Portfolio Holdings
37
Portfolio Turnover Rate
28%
Holdings [Text Block]

Asset Allocation (% of total investments)

Credit Rating Chart
Value
Value
OtherFootnote Reference
0.5%
Commercial Mortgage-Backed Securities
2.5%
Exchange-Traded Funds
4.9%
Short-Term Investments
5.0%
U.S. Treasury Obligations
87.1%
Footnote Description
Footnote
Investment types less than 1% each
Material Fund Change [Text Block]
Updated Prospectus Phone Number 1-800-262-1122
[1] Annualized