Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss), before Tax	$ (41,434)		$ (134,923)
Long-term obligations	740,186		914,688		870,967
Deferred tax expense (benefit)	(16,166)		(52,817)
Accumulated other comprehensive income (loss), net of tax	(25,268)		(82,106)		(66,574)
Income taxes	(96,965)		(59,822)		(115,103)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(12,424)	[1]	(7,304)	[1]
Securities gains (losses)	0		2,277		(288)
Unrealized Gains on Investment Securities Available for Sale
Accumulated Other Comprehensive Income (Loss), before Tax	(16,632)		33,809
Deferred tax expense (benefit)	(6,541)		13,292
Accumulated other comprehensive income (loss), net of tax	(10,091)	[2]	20,517	[2]	16,115	[2]
Income taxes	0	[1]	(917)	[1]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	[1],[2]	1,405	[1],[2]
Securities gains (losses)	0	[1]	2,322	[1]
Funded Status of Defined Benefit Plan
Accumulated Other Comprehensive Income (Loss), before Tax	(17,582)		(158,334)
Deferred tax expense (benefit)	(6,839)		(62,003)
Accumulated other comprehensive income (loss), net of tax	(10,743)	[2]	(96,331)	[2]	(76,206)	[2]
Income taxes	6,689	[1]	4,400	[1]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(10,506)	[1],[2]	(6,836)	[1],[2]
Employee Benefits, prior service costs	(210)	[1]	(210)	[1]
Reclassification adjustment for losses included in income before income taxes	(16,985)	[1]	(11,026)	[1]
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	(17,195)		(11,236)	[1]
Unrealized Loss on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), before Tax	(7,220)		(10,398)
Long-term obligations	(3,281)	[1]	(3,095)	[1]
Deferred tax expense (benefit)	(2,786)		(4,106)
Accumulated other comprehensive income (loss), net of tax	(4,434)	[2]	(6,292)	[2]	(6,483)	[2]
Income taxes	1,363	[1]	1,222	[1]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ (1,918)	[1],[2]	$ (1,873)	[1],[2]

[1] 1 Amounts in parentheses indicate debits to profit/loss.

[2] All amounts are net of tax. Amounts in parentheses indicate debits.