CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension and other post retirement obligations:
Amortization of actuarial (losses) gains included in net periodic pension cost, gross	$ (21,587)	$ 17,443	$ 8,379
Tax effect	5,243	(4,192)	(2,012)
Amortization of actuarial (losses) gains included in net periodic pension cost, net	(16,344)	13,251	6,367
Amortization of prior service cost included in net periodic pension cost, gross	678	200	(471)
Tax effect	(165)	(48)	113
Amortization of prior service cost included in net periodic pension cost, net	513	152	(358)
Other comprehensive (loss) income related to pension and other post retirement obligations, net of taxes	(15,831)	13,403	6,009
Unrealized (losses) gains on investment securities:
Net unrealized holding (losses) gains on investment securities, gross	(818,890)	(166,007)	87,237
Tax effect	198,909	39,900	(20,943)
Other comprehensive (loss) gain related to unrealized (losses) gains on investment securities, net of taxes	(619,981)	(126,107)	66,294
Other comprehensive (loss) income, net of tax	(635,812)	(112,704)	72,303
Net income	188,081	189,694	164,676
Comprehensive (loss) income	(447,731)	76,990	236,979
Accumulated Other Comprehensive (Loss) Income By Component:
Unrealized (loss) for pension and other postretirement obligations	(41,533)	(20,624)	(38,267)
Tax effect	10,232	5,154	9,394
Net unrealized (loss) for pension and other postretirement obligations	(31,301)	(15,470)	(28,873)
Unrealized (loss) gain on investment securities	(864,783)	(45,893)	120,114
Tax effect	209,645	10,736	(29,164)
Net unrealized (loss) gain on investment securities	(655,138)	(35,157)	90,950
Accumulated other comprehensive (loss) income	$ (686,439)	$ (50,627)	$ 62,077