Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Jun. 30, 2014		Dec. 31, 2013		Jun. 30, 2013		Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), before Tax	$ (3,173)				$ (3,173)						$ (41,434)
Deferred tax expense (benefit)	(1,315)				(1,315)						(16,166)
Accumulated other comprehensive income (loss), net of tax	(1,858)		(95,545)		(1,858)		(95,545)		4,057		(25,268)		(100,176)		(82,106)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(503)		(2,237)		(2,456)		(7,468)
Reclassification adjustment for gains included in income before income taxes	822		4,298		4,019		12,896
Unrealized Gains on Investment Securities Available for Sale
Accumulated Other Comprehensive Income (Loss), before Tax	15,374				15,374						(16,632)
Deferred tax expense (benefit)	5,884				5,884						(6,541)
Accumulated other comprehensive income (loss), net of tax	9,490	[1]	(1,824)	[1]	9,490	[1]	(1,824)	[1]	16,490	[1]	(10,091)	[1]	(4,117)	[1]	20,517	[1]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	[1]	0	[1]	0	[1]	0	[1]
Funded Status of Defined Benefit Plan
Accumulated Other Comprehensive Income (Loss), before Tax	(13,563)				(13,563)						(17,582)
Deferred tax expense (benefit)	(5,276)				(5,276)						(6,839)
Accumulated other comprehensive income (loss), net of tax	(8,287)	[1]	(88,863)	[1]	(8,287)	[1]	(88,863)	[1]	(8,790)	[1]	(10,743)	[1]	(91,100)	[1]	(96,331)	[1]
Income taxes	319		2,061		1,563		5,428
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(503)	[1]	(2,237)	[1]	(2,456)	[1]	(7,468)	[1]
Employee Benefits, prior service costs	(53)		(53)		(158)		(158)
Reclassification adjustment for gains included in income before income taxes	(769)		(4,245)		(3,861)		(12,738)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	(822)		(4,298)		(4,019)		(12,896)
Unrealized Loss on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), before Tax	(4,984)				(4,984)						(7,220)
Deferred tax expense (benefit)	(1,923)				(1,923)						(2,786)
Accumulated other comprehensive income (loss), net of tax	(3,061)	[1]	(4,858)	[1]	(3,061)	[1]	(4,858)	[1]	(3,643)	[1]	(4,434)	[1]	(4,959)	[1]	(6,292)	[1]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]

[1] All amounts are net of tax.