Securities - Debt Securities, Held-to-maturity (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	$ 455,900,000	$ 476,647,000
Unrealized Gains	0	0
Unrealized Losses	(68,246,000)	(53,421,000)
Allowance for Credit Losses	0	0	$ 0
Fair Value	387,654,000	423,226,000
Government-sponsored residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	260,271,000	276,493,000
Unrealized Gains	0	0
Unrealized Losses	(40,723,000)	(30,150,000)
Allowance for Credit Losses	0	0
Fair Value	219,548,000	246,343,000
Government-sponsored commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	195,629,000	200,154,000
Unrealized Gains	0	0
Unrealized Losses	(27,523,000)	(23,271,000)
Allowance for Credit Losses	0	0
Fair Value	$ 168,106,000	$ 176,883,000