Investments - Schedule of Fixed Maturities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Amortized Cost, net
Due in one year or less	$ 175,156
Due after one year through five years	1,122,352
Due after five years through ten years	1,651,261
Due after ten years through twenty years	8,041,646
Due after twenty years	7,500,129
Mortgage-backed and asset-backed securities	124,427
Fixed maturities, net of allowance for credit losses	18,614,971
Fair Value
Due in one year or less	174,975
Due after one year through five years	1,118,516
Due after five years through ten years	1,673,707
Due after ten years through twenty years	7,621,151
Due after twenty years	6,321,930
Mortgage-backed and asset-backed securities	123,171
Fixed maturities, fair value	$ 17,033,450	$ 16,503,365