Securities - Securities with Unrealized Losses - Securities Held-to-maturity (Details) - USD ($)	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Securities, Fair Value
Less Than 12 Months	$ 300,510,000
Total	300,510,000
Less Than 12 Months	603,989,000		$ 408,856,000
12 Months or More		$ 29,473,000	27,997,000
Total	633,462,000		436,853,000
Securities, Unrealized (Losses)
Less Than 12 Months	(4,414,000)
Total	(4,414,000)
Less Than 12 Months	(67,104,000)		(3,319,000)
12 Months or More	(5,909,000)		(1,433,000)
Total	(73,013,000)		(4,752,000)
Agency mortgage-backed securities
Securities, Fair Value
Less Than 12 Months	81,550,000
Total	81,550,000
Less Than 12 Months	580,869,000		408,856,000
12 Months or More	29,473,000	$ 29,473,000	27,997,000
Total	610,342,000		436,853,000
Securities, Unrealized (Losses)
Less Than 12 Months	(2,951,000)
Total	(2,951,000)
Less Than 12 Months	(66,582,000)		(3,319,000)
12 Months or More	(5,909,000)		(1,433,000)
Total	(72,491,000)		$ (4,752,000)
U.S. Treasury
Securities, Fair Value
Less Than 12 Months	218,960,000
Total	218,960,000
Securities, Unrealized (Losses)
Less Than 12 Months	(1,463,000)
Total	(1,463,000)
Municipals - Tax Exempt
Securities, Fair Value
Less Than 12 Months	23,120,000
Total	23,120,000
Securities, Unrealized (Losses)
Less Than 12 Months	(522,000)
Total	$ (522,000)