Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Other Comprehensive Income (Loss)
Pre-Tax Amount	$ (14,610)	$ (60,763)	$ (17,042)	$ (137,151)
Tax Benefit	3,017	12,967	3,531	29,274
Net of Tax Amount	(11,593)	(47,796)	(13,511)	(107,877)
Change in net unrealized gains (losses) on available-for-sale debt securities
Other Comprehensive Income (Loss)
Pre-Tax Amount	(12,977)	(42,741)	(13,107)	(114,011)
Tax Benefit	2,696	9,121	2,708	24,325
Net of Tax Amount	(10,281)	(33,620)	(10,399)	(89,686)
Change in interest rate swap
Other Comprehensive Income (Loss)
Pre-Tax Amount	(2,073)	(16,852)	(4,300)	(22,724)
Tax Benefit	426	3,596	902	4,849
Net of Tax Amount	(1,647)	(13,256)	(3,399)	(17,875)
Adjustment to funded status of employee benefit plans
Other Comprehensive Income (Loss)
Pre-Tax Amount	440	(1,170)	365	(416)
Tax Benefit	(105)	250	(79)	100
Net of Tax Amount	$ 335	$ (920)	$ 287	$ (316)