Unaudited Interim Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Fixed Maturities, Available-for-sale, allowance for credit losses	$ 4,315	$ 4,769
Fixed Maturities, Available-for-sale, amortized cost	26,682,558	21,311,087
Fixed maturities, trading, amortized cost	3,369,161	2,682,022
Equity securities, at cost	232,311	148,179
Commercial mortgage and other loans, allowance for credit losses	27,100	20,263
Other invested assets, at fair value	$ 99,566	$ 116,110
Common Stock, Par or Stated Value Per Share	$ 10	$ 10
Common Stock, Shares Authorized	1,000,000	1,000,000
Common Stock, Shares, Issued	250,000	250,000
Common Stock, Shares, Outstanding	250,000	250,000