Comprehensive Income (Loss) - Schedule of Components of Comprehensive Income-Gross and Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income (loss), Gross	$ (80,098)	$ 74,157	$ 22,468	$ 188,916
Unrealized holding gains (losses) during the period, Gross	(8,347)	(60,681)	(23,907)	5,244
Unrealized gains (losses) on securities with credit loss recognized in earnings, Gross	(3,705)	(6,030)	(6,837)	16,401
Amounts reclassified into net income (loss): net realized (gains) losses on disposals and intent-to-sell AFS securities, Gross	43	9,383	(35)	15,487
Amounts reclassified into net income (loss): Credit loss (benefit) expense, Gross	1,233	(864)	3,883	(10,393)
Total unrealized gains (losses) on investment securities, Gross	(10,776)	(58,192)	(26,896)	26,739
Amount reclassified into net income (loss): Net actuarial (gain) loss, Gross	967	757	1,934	1,514
Total defined benefit pension and post-retirement plans, Gross	967	757	1,934	1,514
Other comprehensive income (loss), Gross	(9,809)	(57,435)	(24,962)	28,253
Comprehensive income (loss), Gross	(89,907)	16,722	(2,494)	217,169
Net income (loss), Tax	(16,779)	15,549	3,269	37,734
Unrealized holding gains (losses) during the period, Tax	(1,753)	(12,744)	(5,020)	1,102
Unrealized gains (losses) on securities with credit loss recognized in earnings, Tax	(778)	(1,266)	(1,436)	3,444
Amounts reclassified into net income (loss): net realized (gains) losses on disposals and intent-to-sell AFS securities, Tax	10	1,970	(7)	3,252
Amounts reclassified into net income (loss): Credit loss (benefit) expense, Tax	258	(181)	815	(2,183)
Total unrealized gains (losses) on investment securities, Tax	(2,263)	(12,221)	(5,648)	5,615
Amount reclassified into net income (loss): Net actuarial (gain) loss, Tax	203	159	406	318
Total defined benefit pension and post-retirement plans, Tax	203	159	406	318
Other comprehensive income (loss), Tax	(2,060)	(12,062)	(5,242)	5,933
Comprehensive income (loss), Tax	(18,839)	3,487	(1,973)	43,667
Net income (loss)	(63,319)	58,608	19,199	151,182
Unrealized holding gains (losses) during the period, Net	(6,594)	(47,937)	(18,887)	4,142
Unrealized gains (losses) on securities with credit loss recognized in earnings, Net	(2,927)	(4,764)	(5,401)	12,957
Amounts reclassified into net income (loss): net realized (gains) losses on disposals and intent-to-sell AFS securities, Net	33	7,413	(28)	12,235
Amounts reclassified into net income (loss): Credit loss (benefit) expense, Net	975	(683)	3,068	(8,210)
Total unrealized gains (losses) on investment securities	(8,513)	(45,971)	(21,248)	21,124
Amount reclassified into net income (loss): Net actuarial (gain) loss, Net	764	598	1,528	1,196
Total defined benefit pension and post-retirement plans	764	598	1,528	1,196
Other comprehensive income (loss)	(7,749)	(45,373)	(19,720)	22,320
Comprehensive income (loss)	$ (71,068)	$ 13,235	$ (521)	$ 173,502