Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 divisions	Dec. 31, 2011	Dec. 31, 2010
Basis Of Presentation [Line Items]
Number of branches in which entity operates	29
Deposit pursuant to a payment network arrangement	$ 15,000,000
Individually impaired non-accrual loans	518,100,000	844,000,000
Non-accrual loans	543,333,000	883,021,000
Impaired loans, including accruing troubled debt restructuring	1,062,520,000	1,307,572,000
Accruing troubled debt restructuring	673,400,000	668,500,000	464,100,000
Intangible assets, current carrying value	3,900,000
Unallocated reserve	28,000,000
Decrease in unallocated reserve	20,000,000
Maximum [Member]
Basis Of Presentation [Line Items]
Retail loans and commercial loans, evaluated for impairment	1,000,000
Cash And Cash Equivalents [Member]
Basis Of Presentation [Line Items]
Cash and cash equivalents	68,400,000	73,300,000
Total deposits	15,500,000
Interest earning deposits with banks	14,200,000	10,400,000
Federal funds sold	$ 110,000,000	$ 141,000,000