CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Pension and other post-retirement obligations:
Amortization of actuarial losses (gains) included in net periodic pension cost, gross	$ 290	$ (549)
Tax effect	(71)	134
Amortization of actuarial losses (gains) included in net periodic pension cost, net	219	(415)
Amortization of prior service cost included in net periodic pension cost, gross	160	160
Tax effect	(39)	(39)
Amortization of prior service cost included in net periodic pension cost, net	121	121
Other comprehensive income (loss) related to pension and other post-retirement obligations, net of taxes	340	(294)
Net unrealized (losses) gains on investment securities:
Net unrealized holding (losses) gains on investment securities, gross	(36,066)	91,260
Tax effect	8,802	(22,227)
Net unrealized holding (losses) gains on investment securities, net	(27,264)	69,033
Reclassification adjustment for net losses included in net income, gross	0	52,329
Tax effect	0	(12,714)
Reclassification adjustment for net losses included in net income, net	0	39,615
Other comprehensive (loss) gain related to unrealized (losses) gains on investment securities, net of taxes	(27,264)	108,648
Other comprehensive (loss) income, net of tax	(26,924)	108,354
Net income	40,872	5,798
Comprehensive income	13,948	$ 114,152
Accumulated Other Comprehensive Loss by Component:
Unrecognized prior service cost and net actuarial losses on pension and other post-retirement obligations	(35,668)		$ (36,118)
Tax effect	8,804		8,914
Net unrecognized prior service cost and net actuarial losses on pension and other post-retirement obligations	(26,864)		(27,204)
Unrealized loss on investment securities	(735,056)		(698,990)
Tax effect	178,104		169,302
Net unrealized loss on investment securities	(556,952)		(529,688)
Accumulated other comprehensive loss	$ (583,816)		$ (556,892)