UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 59,113	$ 54,777	$ (86,326)	$ 157,465
Other comprehensive (loss) income, net of tax:
Net change in fair value of securities available for sale	(117,260)	(261,469)	116,285	(860,269)
Net change in fair value of cash flow hedges	(10,980)	(56,062)	(21,573)	(61,482)
Net change in other comprehensive income for defined benefit postretirement plans	(360)	(124)	(1,102)	(371)
Total other comprehensive (loss) income	(128,600)	(317,655)	93,610	(922,122)
Total comprehensive (loss) income	$ (69,487)	$ (262,878)	$ 7,284	$ (764,657)