Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 54,777	$ 37,106	$ 157,465	$ 119,578
Other comprehensive (loss) income, net of tax:
Net change in fair value of securities available for sale	(261,469)	(21,610)	(860,269)	(71,086)
Net change in fair value of cash flow hedges	(56,062)	(5,644)	(61,482)	(17,501)
Net change in other comprehensive income for defined benefit postretirement plans	(124)	426	(371)	1,278
Total other comprehensive (loss) income	(317,655)	(26,828)	(922,122)	(87,309)
Total comprehensive (loss) income	$ (262,878)	$ 10,278	$ (764,657)	$ 32,269