Securities Available for Sale and Held to Maturity - Contractual Maturities of Available for Sale and Held to Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Securities Available for Sale, Amortized Cost [Abstract]
Due in one year or less	$ 39,770
Due after one year through five years	83,002
Due after five years through ten years	50,429
Total amortized cost, before mortgage-backed securities	173,201
Mortgage-backed securities	1,470,109
Securities Available for Sale, Amortized Cost	1,643,310	$ 1,959,007
Securities Available for Sale, Estimated Fair Value [Abstract]
Due in one year or less	39,748
Due after one year through five years	82,927
Due after five years through ten years	50,280
Total fair value, before mortgage-backed securities	172,955
Mortgage-backed securities	1,448,704
Total	1,621,659	1,762,878
Securities Held to Maturity, Amortized Cost [Abstract]
Due in one year or less	0
Due after one year through five years	29,455
Due after five years through ten years	0
Total amortized cost, before mortgage-backed securities	29,455
Mortgage-backed securities	1,351,032
Securities Held to Maturity, Amortized Cost	1,380,487	1,426,279
Securities Held to Maturity, Estimated Fair Value [Abstract]
Due in one year or less	0
Due after one year through five years	28,805
Due after five years through ten years	0
Total fair value, before mortgage-backed securities	28,805
Mortgage-backed securities	1,264,326
Total	$ 1,293,131	$ 1,355,504