CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - 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	$ 141,346	$ 178,119	$ 426,957	$ 391,260
Unrealized gains and losses on available for sale securities
Net losses arising during the period	(37,115)	(57,242)	(37,996)	(148,403)
Less reclassification adjustment for net losses (gains) included in net income	5	(12)	5	(22)
Total	(37,110)	(57,254)	(37,991)	(148,425)
Unrealized gains and losses on derivatives (cash flow hedges)
Net (losses) gains on derivatives arising during the period	0	(85)	(775)	110
Less reclassification adjustment for net (gains) losses included in net income	(43)	(13)	852	293
Total	(43)	(98)	77	403
Defined benefit pension and postretirement benefit plans
Amortization of actuarial net loss	8	132	24	397
Other comprehensive (loss) income, net	(37,145)	(57,220)	(37,890)	(147,625)
Total comprehensive income	$ 104,201	$ 120,899	$ 389,067	$ 243,635