Derivative Investments - Schedule of Fair Value of Derivative Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 101,622	$ 132,821
Derivatives not designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Asset Derivatives	101,622	132,821
Liability Derivatives	58,036	161,351
Derivatives not designated as hedging instruments: | Equity index options | Derivatives, Index Options
Derivatives, Fair Value [Line Items]
Asset Derivatives	101,622	132,821
Derivatives not designated as hedging instruments: | Fixed-index products | Universal Life and Annuity Contracts
Derivatives, Fair Value [Line Items]
Liability Derivatives	142,761	$ 161,351
Derivatives not designated as hedging instruments: | Embedded derivative on reinsurance contract | Funds Withheld Liability
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ (84,725)