v3.26.3
Expense Example
Sep. 28, 2026
USD ($)
LARGE CAP FUND | SIIT LARGE CAP FUND | SIIT LARGE CAP FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 48
Expense Example, with Redemption, 3 Years 151
Expense Example, with Redemption, 5 Years 263
Expense Example, with Redemption, 10 Years 591
LARGE CAP DISCIPLINED EQUITY FUND | SIIT LARGE CAP DISCIPLINED EQUITY FUND | SIIT LARGE CAP DISCIPLINED EQUITY FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 48
Expense Example, with Redemption, 3 Years 151
Expense Example, with Redemption, 5 Years 263
Expense Example, with Redemption, 10 Years 591
LARGE CAP INDEX FUND | SIIT LARGE CAP INDEX FUND | SIIT LARGE CAP INDEX FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 13
Expense Example, with Redemption, 3 Years 42
Expense Example, with Redemption, 5 Years 73
Expense Example, with Redemption, 10 Years 166
S&P 500 INDEX FUND | SIIT S&P 500 Index Fund | SIIT S&P 500 Index Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 12
Expense Example, with Redemption, 3 Years 39
Expense Example, with Redemption, 5 Years 68
Expense Example, with Redemption, 10 Years 154
EXTENDED MARKET INDEX FUND | SIIT Extended Market Index Fund | SIIT Extended Market Index Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 20
Expense Example, with Redemption, 3 Years 64
Expense Example, with Redemption, 5 Years 113
Expense Example, with Redemption, 10 Years 255
SMALL CAP FUND | SIIT SMALL CAP FUND | SIIT SMALL CAP FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 74
Expense Example, with Redemption, 3 Years 230
Expense Example, with Redemption, 5 Years 401
Expense Example, with Redemption, 10 Years 894
SMALL CAP II FUND | SIIT Small Cap II Fund | SIIT Small Cap II Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 74
Expense Example, with Redemption, 3 Years 230
Expense Example, with Redemption, 5 Years 401
Expense Example, with Redemption, 10 Years 894
SMALL/MID CAP EQUITY FUND | SIIT SMALL MID CAP EQUITY FUND | SIIT SMALL MID CAP EQUITY FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 74
Expense Example, with Redemption, 3 Years 230
Expense Example, with Redemption, 5 Years 401
Expense Example, with Redemption, 10 Years 894
U.S. EQUITY FACTOR ALLOCATION FUND | SIIT U.S. Equity Factor Allocation Fund | SIIT U.S. Equity Factor Allocation Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 32
Expense Example, with Redemption, 3 Years 100
Expense Example, with Redemption, 5 Years 174
Expense Example, with Redemption, 10 Years 393
U.S. MANAGED VOLATILITY FUND | SIIT U.S. Managed Volatility Fund | SIIT U.S. Managed Volatility Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 63
Expense Example, with Redemption, 3 Years 199
Expense Example, with Redemption, 5 Years 346
Expense Example, with Redemption, 10 Years 774
GLOBAL MANAGED VOLATILITY FUND | SIIT Global Managed Volatility Fund | SIIT Global Managed Volatility Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 74
Expense Example, with Redemption, 3 Years 230
Expense Example, with Redemption, 5 Years 401
Expense Example, with Redemption, 10 Years 894
WORLD EQUITY EX-US FUND | SIIT WORLD EQUITY EX-US FUND | SIIT WORLD EQUITY EX-US FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 64
Expense Example, with Redemption, 3 Years 202
Expense Example, with Redemption, 5 Years 351
Expense Example, with Redemption, 10 Years 786
SCREENED WORLD EQUITY EX-US FUND | SIIT Screened World Equity Ex-US Fund | SIIT Screened World Equity Ex-US Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 85
Expense Example, with Redemption, 3 Years 265
Expense Example, with Redemption, 5 Years 460
Expense Example, with Redemption, 10 Years 1,025
EMERGING MARKETS EQUITY FUND | SIIT EMERGING MARKETS EQUITY FUND | SIIT EMERGING MARKETS EQUITY FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 104
Expense Example, with Redemption, 3 Years 325
Expense Example, with Redemption, 5 Years 563
Expense Example, with Redemption, 10 Years 1,248
OPPORTUNISTIC INCOME FUND | SIIT Opportunistic Income Fund | SIIT Opportunistic Income Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 57
Expense Example, with Redemption, 3 Years 179
Expense Example, with Redemption, 5 Years 313
Expense Example, with Redemption, 10 Years 701
CORE FIXED INCOME FUND | SIIT CORE FIXED INCOME | SIIT CORE FIXED INCOME - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 38
Expense Example, with Redemption, 3 Years 119
Expense Example, with Redemption, 5 Years 208
Expense Example, with Redemption, 10 Years 468
HIGH YIELD BOND FUND | SIIT HIGH YIELD BOND FUND | SIIT HIGH YIELD BOND FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 57
Expense Example, with Redemption, 3 Years 179
Expense Example, with Redemption, 5 Years 313
Expense Example, with Redemption, 10 Years 701
LONG DURATION FUND | SIIT LONG DURATION FUND | SIIT LONG DURATION FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 39
Expense Example, with Redemption, 3 Years 122
Expense Example, with Redemption, 5 Years 213
Expense Example, with Redemption, 10 Years 480
LONG DURATION CREDIT FUND | SIIT Long Duration Credit Fund | SIIT Long Duration Credit Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 38
Expense Example, with Redemption, 3 Years 119
Expense Example, with Redemption, 5 Years 208
Expense Example, with Redemption, 10 Years 468
ULTRA SHORT DURATION BOND FUND | SIIT Ultra Short Duration Bond Fund | SIIT Ultra Short Duration Bond Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 25
Expense Example, with Redemption, 3 Years 77
Expense Example, with Redemption, 5 Years 135
Expense Example, with Redemption, 10 Years 306
EMERGING MARKETS DEBT FUND | SIIT EMERGING MARKETS DEBT FUND | SIIT EMERGING MARKETS DEBT FUND - CLASS A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 72
Expense Example, with Redemption, 3 Years 224
Expense Example, with Redemption, 5 Years 390
Expense Example, with Redemption, 10 Years 871
REAL RETURN FUND | SIIT Real Return Fund | SIIT Real Return Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 29
Expense Example, with Redemption, 3 Years 90
Expense Example, with Redemption, 5 Years 157
Expense Example, with Redemption, 10 Years 356
LIMITED DURATION BOND FUND | SIIT Limited Duration Bond Fund | SIIT Limited Duration Bond Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 33
Expense Example, with Redemption, 3 Years 103
Expense Example, with Redemption, 5 Years 180
Expense Example, with Redemption, 10 Years 406
INTERMEDIATE DURATION CREDIT FUND | SIIT Intermediate Duration Credit Fund | SIIT Intermediate Duration Credit Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 33
Expense Example, with Redemption, 3 Years 103
Expense Example, with Redemption, 5 Years 180
Expense Example, with Redemption, 10 Years 406
DYNAMIC ASSET ALLOCATION FUND | SIIT Dynamic Asset Allocation Fund | SIIT Dynamic Asset Allocation Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 68
Expense Example, with Redemption, 3 Years 214
Expense Example, with Redemption, 5 Years 373
Expense Example, with Redemption, 10 Years 835
MULTI-ASSET REAL RETURN FUND | SIIT Multi-Asset Real Return Fund | SIIT Multi-Asset Real Return Fund - Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 67
Expense Example, with Redemption, 3 Years 211
Expense Example, with Redemption, 5 Years 368
Expense Example, with Redemption, 10 Years $ 822