Accumulated Other Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income) (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]
Balance January 1				$ 77,080	$ 331,377
Other comprehensive loss before reclassifications to current earnings				(1,598,445)	(213,362)
Amounts reclassified to current earnings from accumulated other comprehensive income				3,214	(16,256)
Current period other comprehensive income (loss), before tax				(1,595,231)	(229,618)
Income tax (expense) benefit				398,807	57,407
Current period other comprehensive income (loss), net of tax		$ (352,450)	$ (61,224)	(1,196,424)	(172,211)
Balance September 30, 2022		(1,119,344)	159,166	(1,119,344)	159,166
Unrealized Gains (Losses) on Securities (1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance January 1	[1]			23,174	263,801
Other comprehensive loss before reclassifications to current earnings	[1]			(1,594,981)	(213,362)
Amounts reclassified to current earnings from accumulated other comprehensive income	[1]			20,274	0
Current period other comprehensive income (loss), before tax	[1]			(1,574,707)	(213,362)
Income tax (expense) benefit	[1]			393,676	53,343
Current period other comprehensive income (loss), net of tax	[1]			(1,181,031)	(160,019)
Balance September 30, 2022	[1]	(1,157,857)	103,782	(1,157,857)	103,782
Pension Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance January 1				(20,668)	(25,118)
Other comprehensive loss before reclassifications to current earnings				0	0
Amounts reclassified to current earnings from accumulated other comprehensive income				1,262	1,768
Current period other comprehensive income (loss), before tax				1,262	1,768
Income tax (expense) benefit				(315)	(442)
Current period other comprehensive income (loss), net of tax				947	1,326
Balance September 30, 2022		(19,721)	(23,792)	(19,721)	(23,792)
Unrealized Gains (Losses) on Cash Flow Hedge Derivatives (2)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance January 1	[2]			74,574	92,694
Other comprehensive loss before reclassifications to current earnings	[2]			(3,464)	0
Amounts reclassified to current earnings from accumulated other comprehensive income	[2]			(18,322)	(18,024)
Current period other comprehensive income (loss), before tax	[2]			(21,786)	(18,024)
Income tax (expense) benefit	[2]			5,446	4,506
Current period other comprehensive income (loss), net of tax	[2]			(16,340)	(13,518)
Balance September 30, 2022	[2]	$ 58,234	$ 79,176	$ 58,234	$ 79,176

[1] The pre-tax amounts reclassified from accumulated other comprehensive income to current earnings are included in "investment securities gains (losses), net" in the consolidated statements of income.

[2] The pre-tax amounts reclassified from accumulated other comprehensive income to current earnings are included in "interest and fees on loans" in the consolidated statements of income.