Other Comprehensive Income (Loss) - Changes in Components of 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
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 1,022,788	$ 1,074,284	$ 1,053,595	$ 1,079,081
Current period changes in other comprehensive income (loss)	(18,367)	(45,304)	(5,242)	(155,230)
Balance at end of year	1,007,431	1,029,645	1,007,431	1,029,645
Accumulated Other Comprehensive (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(166,171)	(155,845)	(179,296)	(45,919)
Current period changes in other comprehensive income (loss)	(18,367)	(45,304)	(5,242)	(155,230)
Balance at end of year	(184,538)	(201,149)	(184,538)	(201,149)
Unrealized Gains (Losses) on Debt Securities Available for Sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(127,036)	(93,701)	(135,482)	1,644
Current period changes in other comprehensive income (loss)	(20,218)	(47,168)	(11,772)	(142,513)
Balance at end of year	(147,254)	(140,869)	(147,254)	(140,869)
Unrealized Gains (Losses) on Swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	2,522	(932)	504	(4,917)
Current period changes in other comprehensive income (loss)	1,845	1,182	3,863	5,167
Balance at end of year	4,367	250	4,367	250
Employee Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(41,657)	(61,212)	(44,318)	(42,646)
Current period changes in other comprehensive income (loss)	6	682	2,667	(17,884)
Balance at end of year	$ (41,651)	$ (60,530)	$ (41,651)	$ (60,530)