Goodwill And Other Intangible Assets (Amortizing Intangible Assets) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 242,619,000	$ 249,112,000
Accumulated amortization	(174,789,000)	(161,214,000)
Net carrying amount	67,830,000	87,898,000
Goodwill impairment			636,216,000
Core Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	213,555,000	215,138,000
Accumulated amortization	(151,790,000)	(135,632,000)
Net carrying amount	61,765,000	79,506,000
Customer Relationships And Other Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	29,064,000	33,974,000
Accumulated amortization	(22,999,000)	(25,582,000)
Net carrying amount	6,065,000	8,392,000
Amortization expense for customer relationships and other intangible assets			$ 2,600,000