Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Available-for-sale securities:
Net unrealized loss during the period	$ (85,368)	$ 68,116	$ 120,333
Reclassification for net gain included in net income		(8)	(29)
Total available-for-sale securities	(85,368)	68,108	120,304
Derivative instruments:
Net unrealized (losses) arising during the year	(23,216)	27,683	(6,672)
Reclassification adjustment for net realized losses included in net income	4,415	11,420	6,832
Total derivative instruments	(18,801)	39,103	160
Defined benefit pension and other postretirement benefit plans:
Net actuarial gain arising during the year	12,052	(5,262)	2,202
Reclassification adjustment for amortization of net loss included in net income	4,102	3,976	5,706
Total (gain) loss recognized in OCI	(16,154)	1,286	(7,908)
Available-for-sale securities:
Net unrealized loss during the period	22,480	(17,937)	(31,686)
Reclassification for net gain included in net income		(2)	(7)
Total securities available-for-sale	(22,480)	17,935	31,679
Derivative instruments:
Net unrealized (losses) arising during the year	6,107	(7,016)	1,727
Reclassification adjustment for net realized losses included in net income	(1,154)	(2,985)	(1,758)
Total derivative instruments	4,953	(10,001)	(31)
Defined benefit pension and other postretirement benefit plans:
Current year actuarial loss	(3,176)	1,375	(580)
Reclassification adjustment for amortization of net loss included in net income	(1,078)	(1,036)	(1,502)
Total defined benefit pension and postretirement benefit plans	(4,254)	339	(2,082)
Available-for-sale securities:
Net unrealized loss during the period	(62,888)	50,179	88,647
Reclassification for net gain included in net income		(6)	(22)
Total available-for-sale securities	(62,888)	50,173	88,625
Derivative instruments:
Net unrealized (losses) arising during the year	(17,109)	20,667	(4,945)
Reclassification adjustment for net realized losses included in net income	3,261	8,435	5,074
Total derivative instruments	(13,848)	29,102	129
Defined benefit pension and other postretirement benefit plans:
Current year actuarial loss	8,876	(3,887)	1,622
Reclassification adjustment for amortization of net loss included in net income	3,024	2,940	4,204
Total defined benefit pension and postretirement benefit plans	11,900	(947)	5,826
Other Comprehensive Income (Loss), Pre-Tax Amount	(88,015)	105,925	128,372
Other Comprehensive Income (Loss), Tax Benefit (Expense)	23,179	(27,597)	(33,792)
Other comprehensive (loss) income, net of tax	$ (64,836)	$ 78,328	$ 94,580