v3.26.1
Shareholder Report, Holdings (Details)
Apr. 30, 2026
C000005563 | U.S. Treasury Notes  
Holdings [Line Items]  
Percent of Net Asset Value 22.10%
C000005563 | Federal National Mortgage Assn.  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
C000005563 | U.S. Treasury Bonds  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
C000005563 | Federal Home Loan Mortgage  
Holdings [Line Items]  
Percent of Net Asset Value 5.70%
C000005563 | Government National Mortgage Assn.  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
C000005563 | Federal Home Loan Mortgage Multifamily Structured PTC  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
C000005563 | UMBS  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000005563 | Benchmark Mortgage Trust  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
C000005563 | Carvana Auto Receivables Trust  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
C000005563 | Bank of America  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
C000005563 | Other0BNY-76105YYY9  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
C000005563 | 0BNY-91282CMZ1  
Holdings [Line Items]  
Percent of Net Asset Value 33.50%
C000005563 | 0BNY-36179WQA9  
Holdings [Line Items]  
Percent of Net Asset Value 25.90%
C000005563 | 0BNY-06051GJE0  
Holdings [Line Items]  
Percent of Net Asset Value 25.40%
C000005563 | 0BNY-34966BAN6  
Holdings [Line Items]  
Percent of Net Asset Value 6.20%
C000005563 | 0BNY-08164HBA4  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
C000005563 | 0BNY-91087BAM2  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
C000005563 | 0BNY-2350366Z8  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000005563 | 0BNY-76105YYY9  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000222343 | U.S. Treasury Notes  
Holdings [Line Items]  
Percent of Net Asset Value 22.10%
C000222343 | Federal National Mortgage Assn.  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
C000222343 | U.S. Treasury Bonds  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
C000222343 | Federal Home Loan Mortgage  
Holdings [Line Items]  
Percent of Net Asset Value 5.70%
C000222343 | Government National Mortgage Assn.  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
C000222343 | Federal Home Loan Mortgage Multifamily Structured PTC  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
C000222343 | UMBS  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000222343 | Benchmark Mortgage Trust  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
C000222343 | Carvana Auto Receivables Trust  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
C000222343 | Bank of America  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
C000222343 | Other0BNY-76105YYY9  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
C000222343 | 0BNY-91282CMZ1  
Holdings [Line Items]  
Percent of Net Asset Value 33.50%
C000222343 | 0BNY-36179WQA9  
Holdings [Line Items]  
Percent of Net Asset Value 25.90%
C000222343 | 0BNY-06051GJE0  
Holdings [Line Items]  
Percent of Net Asset Value 25.40%
C000222343 | 0BNY-34966BAN6  
Holdings [Line Items]  
Percent of Net Asset Value 6.20%
C000222343 | 0BNY-08164HBA4  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
C000222343 | 0BNY-91087BAM2  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
C000222343 | 0BNY-2350366Z8  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000222343 | 0BNY-76105YYY9  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000222342 | U.S. Treasury Notes  
Holdings [Line Items]  
Percent of Net Asset Value 22.10%
C000222342 | Federal National Mortgage Assn.  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
C000222342 | U.S. Treasury Bonds  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
C000222342 | Federal Home Loan Mortgage  
Holdings [Line Items]  
Percent of Net Asset Value 5.70%
C000222342 | Government National Mortgage Assn.  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
C000222342 | Federal Home Loan Mortgage Multifamily Structured PTC  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
C000222342 | UMBS  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000222342 | Benchmark Mortgage Trust  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
C000222342 | Carvana Auto Receivables Trust  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
C000222342 | Bank of America  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
C000222342 | Other0BNY-76105YYY9  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
C000222342 | 0BNY-91282CMZ1  
Holdings [Line Items]  
Percent of Net Asset Value 33.50%
C000222342 | 0BNY-36179WQA9  
Holdings [Line Items]  
Percent of Net Asset Value 25.90%
C000222342 | 0BNY-06051GJE0  
Holdings [Line Items]  
Percent of Net Asset Value 25.40%
C000222342 | 0BNY-34966BAN6  
Holdings [Line Items]  
Percent of Net Asset Value 6.20%
C000222342 | 0BNY-08164HBA4  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
C000222342 | 0BNY-91087BAM2  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
C000222342 | 0BNY-2350366Z8  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000222342 | 0BNY-76105YYY9  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%