v3.26.1
Shareholder Report, Holdings (Details)
May 31, 2026
C000026761 | U.S. Government Agency Securities  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000026761 | U.S. Treasury Securities  
Holdings [Line Items]  
Percent of Net Asset Value 8.80%
C000026761 | U.S. Government Agency Commericial Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 13.00%
C000026761 | Repurchase Agreements  
Holdings [Line Items]  
Percent of Net Asset Value 31.20%
C000026761 | U.S. Government Agency Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 46.40%
C000026763 | U.S. Government Agency Securities  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000026763 | U.S. Treasury Securities  
Holdings [Line Items]  
Percent of Net Asset Value 8.80%
C000026763 | U.S. Government Agency Commericial Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 13.00%
C000026763 | Repurchase Agreements  
Holdings [Line Items]  
Percent of Net Asset Value 31.20%
C000026763 | U.S. Government Agency Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 46.40%
C000168177 | U.S. Government Agency Securities  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000168177 | U.S. Treasury Securities  
Holdings [Line Items]  
Percent of Net Asset Value 8.80%
C000168177 | U.S. Government Agency Commericial Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 13.00%
C000168177 | Repurchase Agreements  
Holdings [Line Items]  
Percent of Net Asset Value 31.20%
C000168177 | U.S. Government Agency Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 46.40%
C000026762 | U.S. Government Agency Securities  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000026762 | U.S. Treasury Securities  
Holdings [Line Items]  
Percent of Net Asset Value 8.80%
C000026762 | U.S. Government Agency Commericial Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 13.00%
C000026762 | Repurchase Agreements  
Holdings [Line Items]  
Percent of Net Asset Value 31.20%
C000026762 | U.S. Government Agency Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 46.40%