Other Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Accumulated other comprehensive income, beginning balance			$ (10,499)		$ (1,895)
Other Comprehensive Income Before Reclassifcations			(5,018)
Amounts Reclassified From Accumulated Other Comprehensive Income			14,177
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	11,355	(61)	9,159		(202)
Accumulated other comprehensive income, ending balance	(1,340)	(2,097)	(1,340)		(2,097)
Net Unrealized Gains on AFS Securities [Member]
Accumulated other comprehensive income, beginning balance			9,711		13,143
Other Comprehensive Income Before Reclassifcations			(5,003)
Amounts Reclassified From Accumulated Other Comprehensive Income			393	[1]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			(4,610)		(814)
Accumulated other comprehensive income, ending balance	5,101	12,329	5,101		12,329
Noncredit-related Impairment [Member]
Accumulated other comprehensive income, beginning balance			(1,938)		(2,062)
Other Comprehensive Income Before Reclassifcations			0
Amounts Reclassified From Accumulated Other Comprehensive Income			1,384
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			1,384		80
Accumulated other comprehensive income, ending balance	(554)	(1,982)	(554)		(1,982)
Net Unrealized Losses on Cash Flow Hedges [Member]
Accumulated other comprehensive income, beginning balance			(1,006)		(1,127)
Other Comprehensive Income Before Reclassifcations			(15)
Amounts Reclassified From Accumulated Other Comprehensive Income			331
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			316		5
Accumulated other comprehensive income, ending balance	(690)	(1,122)	(690)		(1,122)
Pension Benefit Adjustment [Member]
Accumulated other comprehensive income, beginning balance			(17,266)		(11,849)
Other Comprehensive Income Before Reclassifcations			0
Amounts Reclassified From Accumulated Other Comprehensive Income			12,069
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			12,069		527
Accumulated other comprehensive income, ending balance	$ (5,197)	$ (11,322)	$ (5,197)		$ (11,322)

[1] Reported as total other-than-temporary impairment losses on securities in the Consolidated Statement of Income.