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, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	$ 84,641		$ 100,249		$ 88,543		$ 101,820
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	232	[1]	269	[1]	753	[1]	571
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	141,219		178,048		157,612		191,030
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	539	[1]	709	[1]	1,780	[1]	1,856
Impaired Financing Receivable, Average Recorded Investment	225,860		278,297		246,155		292,850
Impaired Financing Receivable, Interest Income, Accrual Method	771	[1]	978	[1]	2,533	[1]	2,427
Real-estate commercial mortage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	27,120		43,197		29,630		43,422
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	113	[1]	172	[1]	394	[1]	370
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	37,962		59,239		46,213		67,064
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	158	[1]	240	[1]	563	[1]	523
Commercial - Secured [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	33,644		25,992		32,528		25,526
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	49	[1]	13	[1]	131	[1]	30
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	22,771		43,420		29,317		46,743
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	34	[1]	32	[1]	115	[1]	65
Commercial - unsecured [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0		59		33		33
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,260		2,555		1,502		2,735
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[1]	2	[1]	4	[1]	4
Real-estate - home equity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	300		583		253		466
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[1]	1	[1]	1	[1]	1
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	14,761		8,045		14,031		6,810
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	17	[1]	7	[1]	49	[1]	11
Real-estate - residential mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	747		1,984		869		1,115
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	4	[1]	17	[1]	25	[1]	30
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	51,365		45,022		52,581		42,555
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	290	[1]	384	[1]	924	[1]	1,144
Construction - Commercial Residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	20,809		25,768		21,730		28,315
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	66	[1]	60	[1]	200	[1]	128
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	12,053		16,232		11,774		21,647
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	39	[1]	37	[1]	121	[1]	94
Construction - Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	2,021		2,666		3,500		2,943
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[1]	6	[1]	2	[1]	12
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	525		2,373		1,641		2,204
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	5	[1]	3	[1]	11
Construction other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	501		997		517		1,073
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	2	[1]	1	[1]	4
Consumer - direct [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	18		7		21		98
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	0
Consumer - Indirect [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	3		0		1		0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	0
Leasing and other and overdrafts [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0		158		14		101
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0

[1] All impaired loans, excluding accruing TDRs, were non-accrual loans. Interest income recognized for the three and nine months ended September 30, 2013 and 2012 represents amounts earned on accruing TDRs.