Accumulated Other Comprehensive Income (Schedule of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income		$ (891,412)		$ (1,086,864)		$ 77,080
Other Comprehensive Income (Loss), before Reclassifications, before Tax		266,176		(1,550,290)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		(5,572)		(1,636)
Other Comprehensive Income (Loss), before Tax		260,604		(1,551,926)
Other Comprehensive Income (Loss), Tax		(65,152)		387,982
Other comprehensive income (loss)		195,452		(1,163,944)		(254,297)
Unrealized Gain Loss on Securities Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income		(915,001)		(1,124,915)	[1]	23,174
Other Comprehensive Income (Loss), before Reclassifications, before Tax		271,442		(1,551,059)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		8,444		20,273
Other Comprehensive Income (Loss), before Tax		279,886		(1,530,786)
Other Comprehensive Income (Loss), Tax		(69,972)		382,697
Other comprehensive income (loss)		209,914		(1,148,089)
Pension Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income		(13,596)		(17,186)		(20,668)
Other Comprehensive Income (Loss), before Reclassifications, before Tax		3,594		3,197
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		1,193		1,446
Other Comprehensive Income (Loss), before Tax		4,787		4,643
Other Comprehensive Income (Loss), Tax		(1,197)		(1,161)
Other comprehensive income (loss)		3,590		3,482
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income		37,185	[2]	55,237	[2]	$ 74,574
Other Comprehensive Income (Loss), before Reclassifications, before Tax	[2]	(8,860)		(2,428)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[2]	(15,209)		(23,355)
Other Comprehensive Income (Loss), before Tax	[2]	(24,069)		(25,783)
Other Comprehensive Income (Loss), Tax	[2]	6,017		6,446
Other comprehensive income (loss)	[2]	$ (18,052)		$ (19,337)

[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.