v3.25.2
Shareholder Report, Holdings (Details)
May 31, 2025
C000072749 | United Kingdom Gilt  
Holdings [Line Items]  
Percent of Net Asset Value 6.00%
C000072749 | Government of Malaysia  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
C000072749 | Republic of Korea  
Holdings [Line Items]  
Percent of Net Asset Value 4.50%
C000072749 | U.S. Treasury Inflation-Indexed Notes  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000072749 | Government of Japan, Inflation-Indexed  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000072749 | U.S. Treasury Notes  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
C000072749 | Bundesrepublik Deutschland Bundesanleihe  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000072749 | Republic of Indonesia  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000072749 | Government of Singapore  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000072749 | Government of Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
C000072749 | Foreign Government Obligations & Municipalities  
Holdings [Line Items]  
Percent of Net Asset Value 42.50%
C000072749 | Corporate Bonds  
Holdings [Line Items]  
Percent of Net Asset Value 25.20%
C000072749 | Asset-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
C000072749 | U.S. Government Agency Obligations (Excluding Mortgage-Backed)  
Holdings [Line Items]  
Percent of Net Asset Value 8.30%
C000072749 | Non-U.S. Government Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
C000072749 | Securities Lending Collateral  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000072749 | Municipal Securities  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000072749 | Bank Loans  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000072749 | Other Holdings Grouping  
Holdings [Line Items]  
Percent of Net Asset Value 6.10%
C000072750 | United Kingdom Gilt  
Holdings [Line Items]  
Percent of Net Asset Value 6.00%
C000072750 | Government of Malaysia  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
C000072750 | Republic of Korea  
Holdings [Line Items]  
Percent of Net Asset Value 4.50%
C000072750 | U.S. Treasury Inflation-Indexed Notes  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000072750 | Government of Japan, Inflation-Indexed  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000072750 | U.S. Treasury Notes  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
C000072750 | Bundesrepublik Deutschland Bundesanleihe  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000072750 | Republic of Indonesia  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000072750 | Government of Singapore  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000072750 | Government of Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
C000072750 | Foreign Government Obligations & Municipalities  
Holdings [Line Items]  
Percent of Net Asset Value 42.50%
C000072750 | Corporate Bonds  
Holdings [Line Items]  
Percent of Net Asset Value 25.20%
C000072750 | Asset-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
C000072750 | U.S. Government Agency Obligations (Excluding Mortgage-Backed)  
Holdings [Line Items]  
Percent of Net Asset Value 8.30%
C000072750 | Non-U.S. Government Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
C000072750 | Securities Lending Collateral  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000072750 | Municipal Securities  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000072750 | Bank Loans  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000072750 | Other Holdings Grouping  
Holdings [Line Items]  
Percent of Net Asset Value 6.10%
C000169957 | United Kingdom Gilt  
Holdings [Line Items]  
Percent of Net Asset Value 6.00%
C000169957 | Government of Malaysia  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
C000169957 | Republic of Korea  
Holdings [Line Items]  
Percent of Net Asset Value 4.50%
C000169957 | U.S. Treasury Inflation-Indexed Notes  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000169957 | Government of Japan, Inflation-Indexed  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000169957 | U.S. Treasury Notes  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
C000169957 | Bundesrepublik Deutschland Bundesanleihe  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000169957 | Republic of Indonesia  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000169957 | Government of Singapore  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000169957 | Government of Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
C000169957 | Foreign Government Obligations & Municipalities  
Holdings [Line Items]  
Percent of Net Asset Value 42.50%
C000169957 | Corporate Bonds  
Holdings [Line Items]  
Percent of Net Asset Value 25.20%
C000169957 | Asset-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
C000169957 | U.S. Government Agency Obligations (Excluding Mortgage-Backed)  
Holdings [Line Items]  
Percent of Net Asset Value 8.30%
C000169957 | Non-U.S. Government Mortgage-Backed Securities  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
C000169957 | Securities Lending Collateral  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000169957 | Municipal Securities  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000169957 | Bank Loans  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000169957 | Other Holdings Grouping  
Holdings [Line Items]  
Percent of Net Asset Value 6.10%