v3.26.1
Shareholder Report, Holdings (Details)
Jun. 30, 2026
C000022342 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000022342 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 47.40%
C000022342 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
C000022342 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
C000022342 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000022342 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
C000022342 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
C000022342 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000022342 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
C000022342 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
C000022342 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000022342 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 47.40%
C000022342 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
C000022342 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
C000022342 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000022342 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000117966 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000117966 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 47.40%
C000117966 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
C000117966 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
C000117966 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000117966 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
C000117966 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
C000117966 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000117966 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
C000117966 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
C000117966 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000117966 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 47.40%
C000117966 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
C000117966 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
C000117966 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000117966 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000117965 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
C000117965 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 47.40%
C000117965 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
C000117965 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
C000117965 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000117965 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
C000117965 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
C000117965 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000117965 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
C000117965 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
C000117965 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000117965 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 47.40%
C000117965 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
C000117965 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
C000117965 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
C000117965 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000022375 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.90%
C000022375 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.40%
C000022375 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.30%
C000022375 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022375 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.40%
C000022375 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.50%
C000022375 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.70%
C000022375 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.00%
C000022375 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022375 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022375 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.80%
C000022375 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80%
C000022375 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022375 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.60%
C000022375 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.90%
C000022375 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.30%
C000022375 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.00%
C000022375 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 26.80%
C000022375 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022376 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.90%
C000022376 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.40%
C000022376 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.30%
C000022376 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022376 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.40%
C000022376 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.50%
C000022376 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.70%
C000022376 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.00%
C000022376 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022376 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022376 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.80%
C000022376 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80%
C000022376 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022376 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.60%
C000022376 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.90%
C000022376 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.30%
C000022376 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.00%
C000022376 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 26.80%
C000022376 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022374 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.90%
C000022374 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.40%
C000022374 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.30%
C000022374 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022374 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.40%
C000022374 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.50%
C000022374 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.70%
C000022374 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.00%
C000022374 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022374 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022374 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.80%
C000022374 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80%
C000022374 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022374 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.60%
C000022374 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.90%
C000022374 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 27.30%
C000022374 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.00%
C000022374 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 26.80%
C000022374 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022418 [Member] | Other countries [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.90%
C000022418 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000022418 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.80%
C000022418 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022418 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.20%
C000022418 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 16.30%
C000022418 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.00%
C000022418 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.60%
C000022418 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 16.50%
C000022418 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.20%
C000022418 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022418 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.40%
C000022418 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.60%
C000022418 [Member] | UNITED STATES  
Holdings [Line Items]  
Percent of Total Investments 58.60%
C000022418 [Member] | UNITED KINGDOM  
Holdings [Line Items]  
Percent of Total Investments 1.50%
C000022418 [Member] | NEW ZEALAND  
Holdings [Line Items]  
Percent of Total Investments 1.50%
C000022418 [Member] | MEXICO  
Holdings [Line Items]  
Percent of Total Investments 2.50%
C000022418 [Member] | KOREA, REPUBLIC OF  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022418 [Member] | JAPAN  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022418 [Member] | INDONESIA  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022418 [Member] | CZECHIA  
Holdings [Line Items]  
Percent of Total Investments 2.60%
C000022418 [Member] | COLOMBIA  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022418 [Member] | BRAZIL  
Holdings [Line Items]  
Percent of Total Investments 6.60%
C000022418 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80%
C000022418 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022418 [Member] | Convertible bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022418 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 35.30%
C000022418 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.70%
C000022418 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022418 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022418 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000022418 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022418 [Member] | Equity [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022418 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.20%
C000022418 [Member] | Exchange Traded Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022418 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.30%
C000022420 [Member] | Other countries [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.90%
C000022420 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000022420 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.80%
C000022420 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022420 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.20%
C000022420 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 16.30%
C000022420 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.00%
C000022420 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.60%
C000022420 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 16.50%
C000022420 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.20%
C000022420 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022420 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.40%
C000022420 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.60%
C000022420 [Member] | UNITED STATES  
Holdings [Line Items]  
Percent of Total Investments 58.60%
C000022420 [Member] | UNITED KINGDOM  
Holdings [Line Items]  
Percent of Total Investments 1.50%
C000022420 [Member] | NEW ZEALAND  
Holdings [Line Items]  
Percent of Total Investments 1.50%
C000022420 [Member] | MEXICO  
Holdings [Line Items]  
Percent of Total Investments 2.50%
C000022420 [Member] | KOREA, REPUBLIC OF  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022420 [Member] | JAPAN  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022420 [Member] | INDONESIA  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022420 [Member] | CZECHIA  
Holdings [Line Items]  
Percent of Total Investments 2.60%
C000022420 [Member] | COLOMBIA  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022420 [Member] | BRAZIL  
Holdings [Line Items]  
Percent of Total Investments 6.60%
C000022420 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80%
C000022420 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022420 [Member] | Convertible bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022420 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 35.30%
C000022420 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.70%
C000022420 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022420 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022420 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000022420 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022420 [Member] | Equity [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022420 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.20%
C000022420 [Member] | Exchange Traded Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022420 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.30%
C000022419 [Member] | Other countries [Member]  
Holdings [Line Items]  
Percent of Total Investments 13.90%
C000022419 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000022419 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.80%
C000022419 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022419 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.20%
C000022419 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 16.30%
C000022419 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.00%
C000022419 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.60%
C000022419 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 16.50%
C000022419 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.20%
C000022419 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022419 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.40%
C000022419 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.60%
C000022419 [Member] | UNITED STATES  
Holdings [Line Items]  
Percent of Total Investments 58.60%
C000022419 [Member] | UNITED KINGDOM  
Holdings [Line Items]  
Percent of Total Investments 1.50%
C000022419 [Member] | NEW ZEALAND  
Holdings [Line Items]  
Percent of Total Investments 1.50%
C000022419 [Member] | MEXICO  
Holdings [Line Items]  
Percent of Total Investments 2.50%
C000022419 [Member] | KOREA, REPUBLIC OF  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022419 [Member] | JAPAN  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022419 [Member] | INDONESIA  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022419 [Member] | CZECHIA  
Holdings [Line Items]  
Percent of Total Investments 2.60%
C000022419 [Member] | COLOMBIA  
Holdings [Line Items]  
Percent of Total Investments 4.00%
C000022419 [Member] | BRAZIL  
Holdings [Line Items]  
Percent of Total Investments 6.60%
C000022419 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.80%
C000022419 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022419 [Member] | Convertible bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.70%
C000022419 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 35.30%
C000022419 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.70%
C000022419 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022419 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022419 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000022419 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022419 [Member] | Equity [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022419 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.20%
C000022419 [Member] | Exchange Traded Funds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022419 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.30%
C000022431 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.20%
C000022431 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000022431 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022431 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.80%
C000022431 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
C000022431 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.80%
C000022431 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.80%
C000022431 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022431 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022431 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000022431 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022431 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000022431 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000022431 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000022431 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000022431 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
C000022431 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022431 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.30%
C000022431 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000022431 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022431 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 41.00%
C000022431 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000022432 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.20%
C000022432 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000022432 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022432 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.80%
C000022432 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
C000022432 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.80%
C000022432 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.80%
C000022432 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022432 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022432 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000022432 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022432 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000022432 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000022432 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000022432 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000022432 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
C000022432 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022432 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.30%
C000022432 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000022432 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022432 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 41.00%
C000022432 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000022430 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.20%
C000022430 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000022430 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022430 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.80%
C000022430 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
C000022430 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.80%
C000022430 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.80%
C000022430 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022430 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022430 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000022430 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022430 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000022430 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000022430 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000022430 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000022430 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
C000022430 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000022430 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.30%
C000022430 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
C000022430 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022430 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 41.00%
C000022430 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
C000022446 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 42.50%
C000022446 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 40.90%
C000022446 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000022446 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
C000022446 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000022446 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.90%
C000022446 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000022446 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
C000022446 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 94.80%
C000022446 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
C000022448 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 42.50%
C000022448 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 40.90%
C000022448 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000022448 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
C000022448 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000022448 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.90%
C000022448 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000022448 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
C000022448 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 94.80%
C000022448 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
C000022447 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 42.50%
C000022447 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 40.90%
C000022447 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
C000022447 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
C000022447 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000022447 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.90%
C000022447 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000022447 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
C000022447 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 94.80%
C000022447 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
C000022568 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022568 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.10%
C000022568 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
C000022568 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.20%
C000022568 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50%
C000022568 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.40%
C000022568 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022568 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.60%
C000022568 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 33.10%
C000022568 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40%
C000022568 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022568 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
C000022568 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.70%
C000022568 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000022568 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.40%
C000022568 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40%
C000022568 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.30%
C000022568 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022568 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
C000022568 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 33.10%
C000022568 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.30%
C000022568 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022569 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022569 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.10%
C000022569 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
C000022569 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.20%
C000022569 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50%
C000022569 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.40%
C000022569 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022569 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.60%
C000022569 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 33.10%
C000022569 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40%
C000022569 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022569 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
C000022569 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.70%
C000022569 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000022569 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.40%
C000022569 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40%
C000022569 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.30%
C000022569 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022569 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
C000022569 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 33.10%
C000022569 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.30%
C000022569 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022567 [Member] | Short term investments Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022567 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.10%
C000022567 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
C000022567 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 4.20%
C000022567 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.50%
C000022567 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.40%
C000022567 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.00%
C000022567 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 7.60%
C000022567 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 33.10%
C000022567 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40%
C000022567 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.80%
C000022567 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
C000022567 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.70%
C000022567 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000022567 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.40%
C000022567 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Total Investments 3.40%
C000022567 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 6.30%
C000022567 [Member] | Short-Term Investments [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022567 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 28.20%
C000022567 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 33.10%
C000022567 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 14.30%
C000022567 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000022640 [Member] | Sixty One To 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022640 [Member] | Thirty One To 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.00%
C000022640 [Member] | Over 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.50%
C000022640 [Member] | Zero To 30 days [Member]  
Holdings [Line Items]  
Percent of Total Investments 73.10%
C000022640 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022640 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 49.10%
C000022640 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 41.60%
C000022642 [Member] | Sixty One To 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022642 [Member] | Thirty One To 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.00%
C000022642 [Member] | Over 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.50%
C000022642 [Member] | Zero To 30 days [Member]  
Holdings [Line Items]  
Percent of Total Investments 73.10%
C000022642 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022642 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 49.10%
C000022642 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 41.60%
C000022641 [Member] | Sixty One To 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000022641 [Member] | Thirty One To 60 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 5.00%
C000022641 [Member] | Over 90 Days [Member]  
Holdings [Line Items]  
Percent of Total Investments 20.50%
C000022641 [Member] | Zero To 30 days [Member]  
Holdings [Line Items]  
Percent of Total Investments 73.10%
C000022641 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.30%
C000022641 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 49.10%
C000022641 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 41.60%
C000022740 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000022740 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
C000022740 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.30%
C000022740 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
C000022740 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000022740 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.50%
C000022740 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022740 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70%
C000022740 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022740 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000022740 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
C000022740 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000022740 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.70%
C000022740 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
C000022740 [Member] | Convertible bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
C000022740 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
C000022740 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
C000022740 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022740 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
C000022740 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
C000022740 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70%
C000022740 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
C000022740 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000022741 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000022741 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
C000022741 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.30%
C000022741 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
C000022741 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000022741 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.50%
C000022741 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022741 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70%
C000022741 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022741 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000022741 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
C000022741 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000022741 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.70%
C000022741 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
C000022741 [Member] | Convertible bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
C000022741 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
C000022741 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
C000022741 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022741 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
C000022741 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
C000022741 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70%
C000022741 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
C000022741 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000022739 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000022739 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
C000022739 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.30%
C000022739 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
C000022739 [Member] | Standard & Poor's, B Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.00%
C000022739 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.50%
C000022739 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 30.70%
C000022739 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70%
C000022739 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022739 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000022739 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
C000022739 [Member] | CCC and below [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000022739 [Member] | Preferred securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.70%
C000022739 [Member] | Term loans [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
C000022739 [Member] | Convertible bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
C000022739 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
C000022739 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
C000022739 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
C000022739 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
C000022739 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
C000022739 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.70%
C000022739 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
C000022739 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
C000073237 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 46.70%
C000073237 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
C000073237 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.90%
C000073237 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000073237 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000073237 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000073237 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 46.70%
C000073237 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.90%
C000073237 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000073237 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
C000073239 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 46.70%
C000073239 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
C000073239 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.90%
C000073239 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000073239 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000073239 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000073239 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 46.70%
C000073239 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.90%
C000073239 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000073239 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
C000073238 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 46.70%
C000073238 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
C000073238 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.90%
C000073238 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000073238 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000073238 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
C000073238 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 46.70%
C000073238 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 50.90%
C000073238 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000073238 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
C000078286 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
C000078286 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
C000078286 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000078286 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.50%
C000078286 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000078286 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.20%
C000078286 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 31.80%
C000078286 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000078286 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40%
C000078286 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000078286 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000078286 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
C000078286 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000078286 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
C000078286 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
C000078286 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 31.80%
C000078286 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 32.30%
C000078286 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40%
C000078286 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000078287 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
C000078287 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
C000078287 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000078287 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.50%
C000078287 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000078287 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.20%
C000078287 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 31.80%
C000078287 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000078287 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40%
C000078287 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000078287 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000078287 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
C000078287 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000078287 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
C000078287 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
C000078287 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 31.80%
C000078287 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 32.30%
C000078287 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40%
C000078287 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000078285 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
C000078285 [Member] | US Government Debt Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
C000078285 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
C000078285 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 9.50%
C000078285 [Member] | Standard & Poor's, BB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000078285 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.20%
C000078285 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 31.80%
C000078285 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000078285 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40%
C000078285 [Member] | Not rated [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
C000078285 [Member] | Foreign government obligations [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000078285 [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
C000078285 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
C000078285 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
C000078285 [Member] | US Government Debt Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
C000078285 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 31.80%
C000078285 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 32.30%
C000078285 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.40%
C000078285 [Member] | Municipal Bonds [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
C000090651 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.70%
C000090651 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000090651 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 28.50%
C000090651 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.40%
C000090651 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000090651 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000090651 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.40%
C000090651 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000090651 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.70%
C000090651 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000090651 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 55.30%
C000090651 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.40%
C000090650 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.70%
C000090650 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000090650 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 28.50%
C000090650 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.40%
C000090650 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000090650 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000090650 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.40%
C000090650 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000090650 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.70%
C000090650 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000090650 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 55.30%
C000090650 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.40%
C000090649 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.70%
C000090649 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
C000090649 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 28.50%
C000090649 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 25.40%
C000090649 [Member] | US Government Corporations and Agencies Securities Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000090649 [Member] | Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000090649 [Member] | Short term investments and other Quality [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.40%
C000090649 [Member] | Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
C000090649 [Member] | Asset-Backed Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 22.70%
C000090649 [Member] | US Government Corporations and Agencies Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
C000090649 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 55.30%
C000090649 [Member] | Short term investments and other [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.40%