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, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	$ 92,892		$ 101,594		$ 93,411		$ 104,375
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	255	[1]	195	[1]	521	[1]	302
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	157,658		191,819		163,733		195,694
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	595	[1]	596	[1]	1,241	[1]	1,147
Impaired Financing Receivable, Average Recorded Investment	250,550		293,413		257,144		300,069
Impaired Financing Receivable, Interest Income, Accrual Method	850	[1]	791	[1]	1,762	[1]	1,449
Real-estate commercial mortage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	30,107		46,502		31,467		46,591
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	125	[1]	127	[1]	281	[1]	198
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	46,002		64,733		49,149		69,677
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	190	[1]	161	[1]	405	[1]	283
Commercial - Secured [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	35,668		21,798		33,816		24,012
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	50	[1]	10	[1]	82	[1]	17
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	27,917		47,437		31,649		47,508
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	39	[1]	20	[1]	81	[1]	33
Commercial - unsecured [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0		13		44		9
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	1,339		2,822		1,587		2,811
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	[1]	1	[1]	3	[1]	2
Real-estate - home equity [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	205		542		237		428
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[1]	0	[1]	1	[1]	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	14,260		6,813		13,787		6,306
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	16	[1]	4	[1]	32	[1]	4
Real-estate - residential mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,494		1,240		1,158		826
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	9	[1]	11	[1]	21	[1]	13
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	53,222		41,731		53,351		41,127
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	309	[1]	370	[1]	634	[1]	760
Construction - Commercial Residential [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	22,267		28,734		22,694		29,567
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	71	[1]	43	[1]	134	[1]	68
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	12,458		24,210		11,582		24,684
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	40	[1]	35	[1]	82	[1]	57
Construction - Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	3,151		2,765		3,995		2,942
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	[1]	4	[1]	2	[1]	6
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,921		2,854		2,064		2,252
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	4	[1]	3	[1]	6
Construction other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	496		1,047		523		1,073
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	[1]	1	[1]	1	[1]	2
Consumer - direct [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	18		8		22		128
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	2		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	23		164		18		128
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, 2013 and 2012 represents amounts earned on accruing TDRs.