Accumulated Other Comprehensive Income (Loss) - Summary of Changes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 1,875,645	$ 1,786,437	$ 1,408,260
Other comprehensive income before reclassifications	(16,132)	55,577
Amounts reclassified from accumulated other comprehensive income	(3,591)	(8,615)
Period change	(19,723)	46,962	49,296
Ending balance	1,912,571	1,875,645	1,786,437
Total
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	74,836	27,874	(21,422)
Period change	(19,723)	46,962	49,296
Ending balance	55,113	74,836	27,874
Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	87,988	38,872
Other comprehensive income before reclassifications	(23,732)	58,513
Amounts reclassified from accumulated other comprehensive income	(4,482)	(9,397)
Period change	(28,214)	49,116
Ending balance	59,774	87,988	38,872
Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(1,594)	(1,141)
Other comprehensive income before reclassifications	109	(1,169)
Amounts reclassified from accumulated other comprehensive income	825	716
Period change	934	(453)
Ending balance	(660)	(1,594)	(1,141)
Unrealized Gains (Losses) on Defined Benefit Plans
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(11,558)	(9,857)
Other comprehensive income before reclassifications	7,491	(1,767)
Amounts reclassified from accumulated other comprehensive income	66	66
Period change	7,557	(1,701)
Ending balance	$ (4,001)	$ (11,558)	$ (9,857)