Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 90,271	$ 68,715	$ 74,999
Investment securities available-for-sale:
Unrealized securities holding gains (losses)	41,905	(1,704)	9,560
Income tax (expense) benefit	(8,780)	532	(1,913)
Net unrealized securities holding gains (losses) before reclassification adjustments, net of taxes	33,125	(1,172)	7,647
Cash flow hedges:
Change in fair value of cash flow hedges	189	(3,620)	(2,829)
Income tax (expense) benefit	(209)	876	803
Net change in fair value of cash flow hedges, net of taxes	(20)	(2,744)	(2,026)
Less reclassification adjustment for change in fair value of cash flow hedges:
Gain (loss) on change in fair value of cash flow hedges	(1,875)	(4,036)	(3,632)
Income tax (expense) benefit	480	1,034	945
Net reclassification adjustment for change in fair value of cash flow hedges	(1,395)	(3,002)	(2,687)
Net change in fair value of cash flow hedges	1,375	258	661
Postretirement benefits:
Adjustment of accumulated obligation for postretirement benefits	(2,119)	1,127	1,135
Income tax (expense) benefit	499	(297)	(294)
Net adjustment of accumulated obligation for postretirement benefits	(1,620)	830	841
Other comprehensive gain (loss), net of taxes	32,880	(84)	9,149
Comprehensive income	$ 123,151	$ 68,631	$ 84,148