Allowance for Loan Losses Impaired Financing Receivables (Details) (Originated Loans, USD $) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 13,297		$ 8,561		$ 5,950
Impaired Financing Receivable, Recorded Investment	110,943	[1]	99,104	[1]	93,448	[1]
Impaired Financing Receivable, Unpaid Principal Balance	127,631	[1]	110,999	[1]	110,055	[1]
Impaired Financing Receivable, Related Allowance	13,297	[1]	8,561	[1]	5,950	[1]
Impaired Financing Receivable, Average Recorded Investment	105,804	[1]	105,464	[1]	95,108	[1]
Residential Portfolio Segment
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	12,424	[1]	12,137	[1]	12,204	[1]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	15,125	[1]	14,845	[1]	15,119	[1]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			1,241	[1]	1,283	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	12,414	[1]	14,067	[1]	13,121	[1]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	12,488	[1]	12,201	[1]	12,425	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	12,398	[1]	14,061	[1]	13,047	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	12,487	[1]	14,161	[1]	13,158	[1]
Impaired Financing Receivable, Related Allowance	1,416	[1]
Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	28,513	[1]	2,776	[1]	11,451	[1]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	35,307	[1]	5,078	[1]	18,207	[1]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			2,866	[1]	72	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,984	[1]	7,406	[1]	326	[1]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	25,006	[1]	4,690	[1]	14,193	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	7,279	[1]	4,367	[1]	308	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	7,350	[1]	9,022	[1]	344	[1]
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9,343	[1]	21,777	[1]	16,874	[1]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	15,478	[1]	20,050	[1]	22,696	[1]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			2,918	[1]	2,914	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,668	[1]	9,864	[1]	4,497	[1]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	9,634	[1]	20,196	[1]	18,027	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	5,657	[1]	9,799	[1]	6,426	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	5,664	[1]	9,878	[1]	6,440	[1]
Commercial Real Estate Construction Financing Receivable
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	[1]	404	[1]	0	[1]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	[1]	2,777	[1]	0	[1]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			0	[1]	0	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	[1]	0	[1]	0	[1]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	[1]	2,943	[1]	0	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[1]	0	[1]	0	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	[1]	0	[1]	0	[1]
Installment
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,846	[1]	2,498	[1]	4,460	[1]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	2,428	[1]	3,502	[1]	4,584	[1]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			1,006	[1]	1,178	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	24,181	[1]	23,548	[1]	19,513	[1]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,881	[1]	2,579	[1]	4,272	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	25,036	[1]	23,320	[1]	20,445	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	25,100	[1]	23,409	[1]	21,024	[1]
Home equity lines
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	977	[1]	997	[1]	1,723	[1]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,222	[1]	1,309	[1]	1,754	[1]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			223	[1]	207	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	6,715	[1]	5,891	[1]	5,944	[1]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	987	[1]	1,004	[1]	1,792	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	6,655	[1]	5,934	[1]	5,656	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	6,655	[1]	5,934	[1]	5,875	[1]
Consumer Credit Card
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	21	[1]	42	[1]	16	[1]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	21	[1]	42	[1]	16	[1]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			307	[1]	296	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	823	[1]	1,025	[1]	966	[1]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	23	[1]	50	[1]	32	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	794	[1]	992	[1]	838	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	794	[1]	992	[1]	838	[1]
Total impaired loans with no related allowance
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	53,124	[1]	40,631	[1]	46,728	[1]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	69,581	[1]	47,603	[1]	62,376	[1]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	50,019	[1]	43,663	[1]	50,741	[1]
Total impaired loans with a related allowance [Member]
Financing Receivable, Impaired [Line Items]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	13,297	[1]	8,561	[1]	5,950	[1]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	55,785	[1]	61,801	[1]	44,367	[1]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	57,819	[1]	58,473	[1]	46,720	[1]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	$ 58,050	[1]	$ 63,396	[1]	$ 47,679	[1]

[1] Note 1: These tables exclude loans fully charged off.Note 2: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.