Loans and Allowance for Credit Losses Average Impaired Loans by Class Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	$ 100,249		$ 96,601		$ 101,820		$ 106,980
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	269	[1]	89	[1]	571	[1]	991	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	178,048		230,022		191,030		283,641
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	709	[1]	618	[1]	1,856	[1]	3,883	[1]
Impaired Financing Receivable, Average Recorded Investment	278,297		326,623		292,850		390,621
Impaired Financing Receivable, Interest Income, Accrual Method	978	[1]	707	[1]	2,427	[1]	4,874	[1]
Real-estate commercial mortage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	43,197		40,448		43,422		43,915
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	172	[1]	78	[1]	370	[1]	568	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	59,239		73,076		67,064		79,898
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	240	[1]	140	[1]	523	[1]	1,129	[1]
Commercial - Secured [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	25,992		34,474		25,526		31,426
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	13	[1]	10	[1]	30	[1]	171	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	43,420		51,851		46,743		86,061
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	32	[1]	14	[1]	65	[1]	1,213	[1]
Commercial - unsecured [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	59		149		33		221
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	3	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,555		2,231		2,735		4,132
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	2	[1]	1	[1]	4	[1]	34	[1]
Real-estate - home equity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	583		0		466		0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	[1]	0	[1]	1	[1]	0	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	8,045		0		6,810		0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	7	[1]	0	[1]	11	[1]	0	[1]
Real-estate - residential mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,984		0		1,115		5,303
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	17	[1]	0	[1]	30	[1]	43	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	45,022		66,892		42,555		57,033
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	384	[1]	462	[1]	1,144	[1]	1,039	[1]
Construction - Commercial Residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	25,768		18,528		28,315		23,154
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	60	[1]	1	[1]	128	[1]	185	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	16,232		31,132		21,647		53,004
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	37	[1]	1	[1]	94	[1]	449	[1]
Construction - Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	2,666		2,902		2,943		2,911
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	6	[1]	0	[1]	12	[1]	21	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,373		718		2,204		1,100
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	5	[1]	0	[1]	11	[1]	17	[1]
Construction other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	997		1,556		1,073		1,093
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	2	[1]	0	[1]	4	[1]	0	[1]
Consumer - direct [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0		100		0		50
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	0	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	7		2,477		98		1,260
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	2	[1]
Leasing and other and overdrafts [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	158		89		101		60
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]

[1] All impaired loans, excluding accruing troubled debt restructurings, were non-accrual loans. Interest income recognized for the three and nine months ended September 30, 2012 and 2011 represent amounts earned on accruing troubled debt restructurings.