v3.25.4
Shareholder Report, Holdings (Details)
Dec. 31, 2025
C000013875 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.20%
C000013875 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 99.70%
C000013875 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000013876 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 43.80%
C000013876 [Member] | Short Term Treasury Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 26.20%
C000013876 [Member] | Short Term Variable Rate securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 18.70%
C000013876 [Member] | Short Term Government Agency Debt [Member]  
Holdings [Line Items]  
Percent of Total Investments 11.30%
C000013877 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 99.70%
C000013877 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
C000013878 [Member] | Other [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.00%
C000013878 [Member] | AUSTRALIA  
Holdings [Line Items]  
Percent of Total Investments 4.50%
C000013878 [Member] | DENMARK  
Holdings [Line Items]  
Percent of Total Investments 3.00%
C000013878 [Member] | FRANCE  
Holdings [Line Items]  
Percent of Total Investments 10.10%
C000013878 [Member] | GERMANY  
Holdings [Line Items]  
Percent of Total Investments 10.20%
C000013878 [Member] | JAPAN  
Holdings [Line Items]  
Percent of Total Investments 21.10%
C000013878 [Member] | NETHERLANDS  
Holdings [Line Items]  
Percent of Total Investments 6.00%
C000013878 [Member] | SPAIN  
Holdings [Line Items]  
Percent of Total Investments 7.60%
C000013878 [Member] | SWITZERLAND  
Holdings [Line Items]  
Percent of Total Investments 5.60%
C000013878 [Member] | UNITED KINGDOM  
Holdings [Line Items]  
Percent of Total Investments 8.20%
C000013878 [Member] | UNITED STATES  
Holdings [Line Items]  
Percent of Total Investments 13.70%
C000013878 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10%
C000013878 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 99.90%
C000013879 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 99.70%
C000013879 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
C000013880 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.30%
C000013880 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 96.10%
C000013880 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 2.60%
C000013880 [Member] | Rights Warrants [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.00%
C000013881 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
C000013881 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 98.70%
C000013881 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.00%
C000013881 [Member] | Rights Warrants [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.00%
C000013882 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 99.70%
C000013882 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
C000013883 [Member] | Common Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 98.10%
C000013883 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000013883 [Member] | Investment Companies [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.80%
C000013884 [Member] | N R not rated [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.20% [1]
C000013884 [Member] | Moody's, Aaa Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 9.50% [1]
C000013884 [Member] | N A not applicable [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.30% [1]
C000013884 [Member] | Standard & Poor's, AA Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 49.10% [1]
C000013884 [Member] | Standard & Poor's, A Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 12.90% [1]
C000013884 [Member] | Standard & Poor's, BBB Rating [Member]  
Holdings [Line Items]  
Percent of Total Investments 18.00% [1]
C000013884 [Member] | BB or Lower [Member]  
Holdings [Line Items]  
Percent of Total Investments 8.00% [1]
C000013884 [Member] | Investments Purchased with Collateral from Securities Lending [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.30%
C000013884 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.10%
C000013884 [Member] | Bank Loan Obligations [Member]  
Holdings [Line Items]  
Percent of Total Investments 1.40%
C000013884 [Member] | Corporate Bond Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 30.70%
C000013884 [Member] | Preferred Stock [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.00%
C000013884 [Member] | Government Bonds [Member]  
Holdings [Line Items]  
Percent of Total Investments 50.90%
C000013884 [Member] | Structured Assets [Member]  
Holdings [Line Items]  
Percent of Total Investments 15.60%
C000135632 [Member] | Repurchase Agreements [Member]  
Holdings [Line Items]  
Percent of Total Investments 0.10% [2]
C000135632 [Member] | International Equity [Member]  
Holdings [Line Items]  
Percent of Total Investments 10.10% [2]
C000135632 [Member] | U S Equity [Member]  
Holdings [Line Items]  
Percent of Total Investments 39.90% [2]
C000135632 [Member] | Fixed Income Securities [Member]  
Holdings [Line Items]  
Percent of Total Investments 49.90% [2]
[1] Credit quality ratings are based on the Bloomberg Barclays methodology, which uses the median rating of those compiled by the Moody’s, Standard & Poor’s and Fitch ratings agencies. If ratings are available from only two of these agencies, the lower rating is used. When only one rating is available, that one is used. These ratings are subject to change without notice.
[2] Affiliated investment companies (Underlying Funds), except for repurchase agreements.