Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 48,657	$ 51,172	$ (145,439)	$ 102,688
After Tax Amount
Net change in fair value of securities available for sale	(58,486)	(246,775)	233,545	(598,800)
Net change in fair value of cash flow hedges	(32,271)	(1,611)	(10,593)	(5,420)
Net change in other comprehensive income for defined benefit postretirement plans	(361)	(123)	(742)	(247)
Total other comprehensive (loss) income	(91,118)	(248,509)	222,210	(604,467)
Total comprehensive (loss) income	$ (42,461)	$ (197,337)	$ 76,771	$ (501,779)