Debt Securities - Maturity Schedule (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Available-for-Sale, Amortized Cost
Due within one year	$ 54,947
Due after one year through five years	798,503
Due after five years through ten years	30,724
Due after ten years	37,701
Total before mortgage-backed securities	921,875
Mortgage-backed securities	4,049,635
Amortized Cost	4,971,510	$ 5,283,253
Available-for-Sale, Fair Value
Due within one year	52,934
Due after one year through five years	751,219
Due after five years through ten years	29,744
Due after ten years	35,073
Total before mortgage-backed securities	868,970
Mortgage-backed securities	3,630,571
Debt securities, available-for-sale	4,499,541	4,785,719
Held-to-Maturity, Amortized Cost
Due within one year	8,550
Due after one year through five years	937,001
Due after five years through ten years	180,213
Due after ten years	1,367,269
Total before mortgage-backed securities	2,493,033
Mortgage-backed securities	907,370
Amortized Cost	3,400,403	3,502,411
Held-to-Maturity, Fair Value
Due within one year	8,513
Due after one year through five years	866,167
Due after five years through ten years	171,432
Due after ten years	1,172,667
Total before mortgage-backed securities	2,218,779
Mortgage-backed securities	828,290
Total	$ 3,047,069	$ 3,180,194