Intangible Assets (Summary Of Gross Goodwill And Accumulated Impairment Losses And Write-Offs Detailed By Reportable Segments) (Details) (USD $)	3 Months Ended				12 Months Ended
	Mar. 31, 2012	Jun. 30, 2011	Mar. 31, 2011		Dec. 31, 2011	Dec. 31, 2010
Indefinite-lived Intangible Assets by Segment [Line Items]
Gross goodwill	$ 334,237,000		$ 333,654,000		$ 333,654,000	$ 333,654,000
Accumulated impairments	(114,123,000)		(114,123,000)		(114,123,000)	(104,023,000)
Accumulated divestiture related write-offs	(85,872,000)		(67,451,000)		(85,872,000)	(67,451,000)
Goodwill	134,242,000		152,080,000		133,659,000	162,180,000
Additions	583,000
Impairments			(10,100,000)	[1],[2]
Divestitures		16,400,000
Net change in goodwill	583,000		(10,100,000)
Non-Strategic [Member]
Indefinite-lived Intangible Assets by Segment [Line Items]
Gross goodwill	199,995,000		199,995,000		199,995,000	199,995,000
Accumulated impairments	(114,123,000)		(114,123,000)		(114,123,000)	(104,023,000)
Accumulated divestiture related write-offs	(85,872,000)		(67,451,000)		(85,872,000)	(67,451,000)
Goodwill			18,421,000			28,521,000
Additions
Impairments			(10,100,000)
Divestitures
Net change in goodwill			(10,100,000)
Regional Banking [Member]
Indefinite-lived Intangible Assets by Segment [Line Items]
Gross goodwill	36,238,000		36,238,000		36,238,000	36,238,000
Goodwill	36,238,000		36,238,000		36,238,000	36,238,000
Additions
Divestitures
Net change in goodwill
Capital Markets [Member]
Indefinite-lived Intangible Assets by Segment [Line Items]
Gross goodwill	98,004,000		97,421,000		97,421,000	97,421,000
Accumulated impairments
Accumulated divestiture related write-offs
Goodwill	98,004,000		97,421,000		97,421,000	97,421,000
Additions	583,000
Divestitures
Net change in goodwill	$ 583,000

[1] See Note 16—Restructuring, Repositioning, and Efficiency for further details related to goodwill impairments.

[2] See Note 2—Acquisitions and Divestitures for further details regarding goodwill related to divestitures.