Debt Securities Available for Sale - Securities Available-for-Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,218,160	$ 1,515,941
Gross Unrealized Gains	176	141
Gross Unrealized (Losses)	(199,957)	(187,448)
Debt securities available for sale	1,018,379	1,328,634
U.S. government and agency obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	96,364	67,771
Gross Unrealized Gains	27	0
Gross Unrealized (Losses)	(2,608)	(4,205)
Debt securities available for sale	93,783	63,566
Mortgage-backed securities and collateralized mortgage obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,026,493	1,351,929
Gross Unrealized Gains	140	135
Gross Unrealized (Losses)	(182,373)	(170,337)
Debt securities available for sale	844,260	1,181,727
Municipal obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,772	3,697
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	(108)	(122)
Debt securities available for sale	2,664	3,575
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	92,531	92,544
Gross Unrealized Gains	9	6
Gross Unrealized (Losses)	(14,868)	(12,784)
Debt securities available for sale	$ 77,672	$ 79,766