Debt Securities - Maturity Schedule (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Available-for-Sale, Amortized Cost
Due within one year	$ 535,800
Due after one year through five years	306,245
Due after five years through ten years	21,096
Due after ten years	30,766
Total before mortgage-backed securities	893,907
Mortgage-backed securities	3,628,745
Amortized Cost	4,522,652	$ 4,656,310
Available-for-Sale, Fair Value
Due within one year	524,798
Due after one year through five years	294,573
Due after five years through ten years	19,840
Due after ten years	28,988
Total before mortgage-backed securities	868,199
Mortgage-backed securities	3,304,113
Debt securities, available for sale	4,172,312	4,245,205
Held-to-Maturity, Amortized Cost
Due within one year	19,713
Due after one year through five years	952,582
Due after five years through ten years	217,784
Due after ten years	1,284,608
Total before mortgage-backed securities	2,474,687
Mortgage-backed securities	786,888
Amortized Cost	3,261,575	3,294,847
Held-to-Maturity, Fair Value
Due within one year	19,694
Due after one year through five years	907,008
Due after five years through ten years	208,141
Due after ten years	1,083,738
Total before mortgage-backed securities	2,218,581
Mortgage-backed securities	734,842
Total	$ 2,953,423	$ 2,968,570