Loans and Allowance for Credit Losses Average Impaired Loans by Class Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	$ 65,285		$ 92,892		$ 64,154		$ 93,411
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	182	[1]	255	[1]	364	[1]	521
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	134,898		157,658		136,588		163,733
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	521	[1]	595	[1]	1,041	[1]	1,241
Impaired Financing Receivable, Average Recorded Investment	200,183		250,550		200,742		257,144
Impaired Financing Receivable, Interest Income, Accrual Method	703	[1]	850	[1]	1,405	[1]	1,762
Real-estate commercial mortage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	23,162		30,107		23,606		31,467
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	80	[1]	125	[1]	166	[1]	281
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	38,455		46,002		37,580		49,149
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	132	[1]	190	[1]	264	[1]	405
Commercial - Secured [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	21,695		35,668		21,591		33,816
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	34	[1]	50	[1]	69	[1]	82
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	21,652		27,917		21,876		31,649
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	33	[1]	39	[1]	71	[1]	81
Commercial - unsecured [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0		0		0		44
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	757		1,339		854		1,587
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[1]	1	[1]	2	[1]	3
Real-estate - home equity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	300		205		300		237
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	[1]	0	[1]	1	[1]	1
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	14,049		14,260		14,145		13,787
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	28	[1]	16	[1]	48	[1]	32
Real-estate - residential mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	857		1,494		571		1,158
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	5	[1]	9	[1]	6	[1]	21
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	51,153		53,222		51,134		53,351
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	300	[1]	309	[1]	594	[1]	634
Construction - Commercial Residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	17,853		22,267		16,482		22,694
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	62	[1]	71	[1]	122	[1]	134
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	7,676		12,458		9,977		11,582
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	27	[1]	40	[1]	62	[1]	82
Construction - Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,418		3,151		1,604		3,995
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	2
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	723		1,921		547		2,064
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	3
Construction other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	413		496		458		523
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	0	[1]	1
Consumer - direct [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	16		18		14		22
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	4		2		3		1
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		23		0		18
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 six months ended June 30, 2014 and 2013 represents amounts earned on accruing TDRs.