Stockholders' Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (53,935)	$ 80,069
Net change in unrealized gain or loss	$ (367,437)	$ (48,569)	(961,892)	(143,924)
Reclassification of net income or loss realized and included in earnings	(1,441)	(6,425)	(10,849)	(9,337)
Valuation adjustments to pension plan attributable to VERIP and curtailment				59,606
Other valuation adjustments to employee benefit plans			(8,397)	(10,651)
Amortization of unrealized net gain or loss on securities transferred to HTM	434	(33)	961	(134)
Income tax (expense) benefit	83,250	12,363	221,331	24,569
Ending Balance	(812,781)	198	(812,781)	198
Accumulated Other Comprehensive Loss Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			11,037	171,224
Net change in unrealized gain or loss			(844,250)	(144,715)
Reclassification of net income or loss realized and included in earnings			1,707	2,166
Transfer of net unrealized loss from AFS to HTM securities portfolio			15,405
Income tax (expense) benefit			186,685	31,952
Ending Balance	(629,416)	60,627	(629,416)	60,627
Held to Maturity Securities Transferred from AFS [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			153	276
Transfer of net unrealized loss from AFS to HTM securities portfolio			(15,405)
Amortization of unrealized net gain or loss on securities transferred to HTM			961	(134)
Income tax (expense) benefit			3,260	30
Ending Balance	(11,031)	172	(11,031)	172
Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(80,946)	(125,573)
Reclassification of net income or loss realized and included in earnings			1,963	3,970
Valuation adjustments to pension plan attributable to VERIP and curtailment				59,606
Other valuation adjustments to employee benefit plans			(8,397)	(10,651)
Income tax (expense) benefit			1,452	(11,783)
Ending Balance	(85,928)	(84,431)	(85,928)	(84,431)
Gains and Losses on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			16,284	39,511
Net change in unrealized gain or loss			(118,110)	353
Reclassification of net income or loss realized and included in earnings			(14,519)	(19,941)
Income tax (expense) benefit			29,934	4,370
Ending Balance	(86,411)	24,293	(86,411)	24,293
Equity Method Investment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(463)	(5,369)
Net change in unrealized gain or loss			468	438
Reclassification of net income or loss realized and included in earnings				4,468
Ending Balance	$ 5	$ (463)	$ 5	$ (463)