Loans and Allowance for Credit Losses Troubled Debt Restructuring Modification (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		15 Months Ended
	Sep. 30, 2013 loans	Sep. 30, 2012 loans	Sep. 30, 2013 loans	Sep. 30, 2012 loans	Sep. 30, 2013 loans
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	25	23	120	79
Recorded investment of loans modified as TDRs during the reporting periods	$ 10,108	$ 7,656	$ 28,368	$ 46,575
Number of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	41	32	91	51
Recorded investment of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	9,247	13,003	21,427	20,135
Real-estate commercial mortage [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	4	2	13	15
Recorded investment of loans modified as TDRs during the reporting periods	3,774	1,404	8,428	18,004
Number of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	3	6	9	7
Recorded investment of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	1,299	6,358	3,712	7,442
Real-estate - residential mortgage [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	5	9	44	33
Recorded investment of loans modified as TDRs during the reporting periods	836	3,350	6,861	11,465
Number of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	29	15	55	26
Recorded investment of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	7,224	2,977	14,808	6,763
Construction - commercial residential [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	2	2	6	8
Recorded investment of loans modified as TDRs during the reporting periods	4,427	741	9,542	11,178
Number of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	0	3	2	4
Recorded investment of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	0	836	608	2,691
Real-estate - home equity [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	14	1	42	7
Recorded investment of loans modified as TDRs during the reporting periods	1,071	132	2,928	692
Number of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	7	3	20	8
Recorded investment of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	507	273	1,609	653
Commercial - Secured [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	0	7	7	14
Recorded investment of loans modified as TDRs during the reporting periods	0	737	592	3,944
Number of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	2	3	5	4
Recorded investment of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	217	1,267	690	1,294
Consumer Other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	0	1	0	1
Recorded investment of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	0	335	0	335
Commercial - unsecured [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	0	0	1	0
Recorded investment of loans modified as TDRs during the reporting periods	0	0	15	0
Construction other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	0	1	0	1
Recorded investment of loans modified as TDRs during the reporting periods	0	335	0	335
Construction - Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	0	1	0	1
Recorded investment of loans modified as TDRs during the reporting periods	0	957	0	957
Number of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	0		0	1	1
Recorded investment of loans modified as TDRs within the previous 12 months which had a payment default during the reporting period	0		0	957	957
Consumer - direct [Member]
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDRs during the reporting periods	0	0	7	0
Recorded investment of loans modified as TDRs during the reporting periods	$ 0	$ 0	$ 2	$ 0