Certain Long-Duration Contracts With Guarantees (Separate Account Investment Options) (Details) - Annuity Contracts - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Separate Account Investment [Line Items]
Separate Account Investment Options	$ 31,777,976	$ 141,400,634
Equity funds
Fair Value, Separate Account Investment [Line Items]
Separate Account Investment Options	20,796,440	83,132,748
Bond funds
Fair Value, Separate Account Investment [Line Items]
Separate Account Investment Options	9,651,046	55,850,849
Money market funds
Fair Value, Separate Account Investment [Line Items]
Separate Account Investment Options	$ 1,330,490	$ 2,417,037