Debt Securities - Maturity of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Amortized Cost
Due in one year or less	$ 105,794
Due after one year through five years	363,407
Due after five years through ten years	369,029
Due after ten years	1,825,691
Amortized Cost	2,663,921	$ 2,772,453
Fair Value
Due in one year or less	103,746
Due after one year through five years	340,503
Due after five years through ten years	337,071
Due after ten years	1,602,230
Fair Value	2,383,550	2,461,393
Amortized Cost
Due after one year through five years	43,594
Due after five years through ten years	63,632
Due after ten years	800,333
Amortized Cost	907,559	918,312
Fair Value
Due after one year through five years	41,147
Due after five years through ten years	57,859
Due after ten years	681,647
Fair Value	$ 780,653	$ 785,295