Change in Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ 1,791,726
Other comprehensive income (loss) before reclassifications	(92,979)	$ 39,959	$ 39,563
Less: Amounts reclassified from accumulated other comprehensive (loss) income	(796)	(7,453)	(668)
Net current-period other comprehensive income (loss)	(93,775)	32,506	38,895
Ending Balance	1,939,099	1,791,726
Total
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	56,007	23,501	(15,394)
Ending Balance	(37,768)	56,007	23,501
Net change in investment securities available for sale
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	59,882	26,927	(14,553)
Other comprehensive income (loss) before reclassifications	(93,503)	39,853	41,733
Less: Amounts reclassified from accumulated other comprehensive (loss) income	(252)	(6,898)	(253)
Net current-period other comprehensive income (loss)	(93,755)	32,955	41,480
Ending Balance	(33,873)	59,882	26,927
Net change in investment securities held to maturity
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	276	468	779
Other comprehensive income (loss) before reclassifications	0	0	(2)
Less: Amounts reclassified from accumulated other comprehensive (loss) income	(101)	(192)	(309)
Net current-period other comprehensive income (loss)	(101)	(192)	(311)
Ending Balance	175	276	468
Net change in defined benefit plan
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(4,788)	(3,317)	834
Other comprehensive income (loss) before reclassifications	162	(1,445)	(4,045)
Less: Amounts reclassified from accumulated other comprehensive (loss) income	(65)	(26)	(106)
Net current-period other comprehensive income (loss)	97	(1,471)	(4,151)
Ending Balance	(4,691)	(4,788)	(3,317)
Net unrealized gains on terminated cash flow hedges:
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	646	(577)	(2,454)
Other comprehensive income (loss) before reclassifications	0	1,560	1,877
Less: Amounts reclassified from accumulated other comprehensive (loss) income	(378)	(337)	0
Net current-period other comprehensive income (loss)	(378)	1,223	1,877
Ending Balance	268	646	(577)
Net change in equity method investments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(9)	0	0
Other comprehensive income (loss) before reclassifications	362	(9)	0
Less: Amounts reclassified from accumulated other comprehensive (loss) income	0	0	0
Net current-period other comprehensive income (loss)	362	(9)	0
Ending Balance	$ 353	$ (9)	$ 0