v3.25.3
Shareholder Report, Holdings (Details) - C000111140
Aug. 31, 2025
Federal National Mortgage Assn.  
Holdings [Line Items]  
Percent of Net Asset Value 48.90%
Federal Home Loan Mortgage  
Holdings [Line Items]  
Percent of Net Asset Value 26.80%
Government National Mortgage Assn.  
Holdings [Line Items]  
Percent of Net Asset Value 25.40%
UMBS  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
U.S. Government & Agency Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 104.30%
Other Holdings Grouping  
Holdings [Line Items]  
Percent of Net Asset Value (4.30%)