Loans, Impaired Loans Recorded Investment, Unpaid Principal Balance, Related Allowance, Average Recorded Investment, and Interest Income Recognized (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 339,050	$ 355,160
Unpaid Principal Balance	365,588	394,588
Related Allowance	50,884	46,483
Average Recorded Investment	347,731	378,277
Interest Income Recognized	$ 1,826	$ 10,228
Net Recorded Investment of the Impaired Loans	79.00%	78.00%
Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 244,990	$ 221,012
Unpaid Principal Balance	265,352	236,876
Related Allowance	50,884	46,483
Average Recorded Investment	251,603	237,729
Interest Income Recognized	1,665	8,383
Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	94,060	134,148
Unpaid Principal Balance	100,236	157,712
Related Allowance	0	0
Average Recorded Investment	96,128	140,548
Interest Income Recognized	161	1,845
Commercial and industrial
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	195,743	215,255
Unpaid Principal Balance	210,273	242,676
Related Allowance	26,686	21,617
Average Recorded Investment	203,675	229,191
Interest Income Recognized	398	4,031
Commercial and industrial | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	124,408	101,770
Unpaid Principal Balance	135,061	107,813
Related Allowance	26,686	21,617
Average Recorded Investment	130,361	111,211
Interest Income Recognized	305	2,512
Commercial and industrial | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	71,335	113,485
Unpaid Principal Balance	75,212	134,863
Related Allowance	0	0
Average Recorded Investment	73,314	117,980
Interest Income Recognized	93	1,519
Commercial real estate — owner occupied
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	23,457	15,034
Unpaid Principal Balance	26,242	17,907
Related Allowance	1,766	295
Average Recorded Investment	23,627	15,870
Interest Income Recognized	113	412
Commercial real estate — owner occupied | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	14,918	6,595
Unpaid Principal Balance	16,833	8,641
Related Allowance	1,766	295
Average Recorded Investment	15,045	7,111
Interest Income Recognized	113	274
Commercial real estate — owner occupied | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	8,539	8,439
Unpaid Principal Balance	9,409	9,266
Related Allowance	0	0
Average Recorded Investment	8,582	8,759
Interest Income Recognized	0	138
Commercial and business lending
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	219,200	230,289
Unpaid Principal Balance	236,515	260,583
Related Allowance	28,452	21,912
Average Recorded Investment	227,302	245,061
Interest Income Recognized	511	4,443
Commercial and business lending | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	139,326	108,365
Unpaid Principal Balance	151,894	116,454
Related Allowance	28,452	21,912
Average Recorded Investment	145,406	118,322
Interest Income Recognized	418	2,786
Commercial and business lending | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	79,874	121,924
Unpaid Principal Balance	84,621	144,129
Related Allowance	0	0
Average Recorded Investment	81,896	126,739
Interest Income Recognized	93	1,657
Commercial real estate — investor
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	22,836	33,340
Unpaid Principal Balance	23,716	34,155
Related Allowance	319	3,541
Average Recorded Investment	22,913	38,234
Interest Income Recognized	371	2,124
Commercial real estate — investor | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	16,018	27,196
Unpaid Principal Balance	16,497	27,677
Related Allowance	319	3,541
Average Recorded Investment	16,060	31,142
Interest Income Recognized	371	2,124
Commercial real estate — investor | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	6,818	6,144
Unpaid Principal Balance	7,219	6,478
Related Allowance	0	0
Average Recorded Investment	6,853	7,092
Interest Income Recognized	0	0
Real estate construction
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,574	1,203
Unpaid Principal Balance	1,888	1,566
Related Allowance	533	441
Average Recorded Investment	1,594	1,321
Interest Income Recognized	32	67
Real estate construction | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,349	1,203
Unpaid Principal Balance	1,663	1,566
Related Allowance	533	441
Average Recorded Investment	1,369	1,321
Interest Income Recognized	32	67
Real estate construction | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	225	0
Unpaid Principal Balance	225	0
Related Allowance	0	0
Average Recorded Investment	225	0
Interest Income Recognized	0	0
Commercial real estate lending
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	24,410	34,543
Unpaid Principal Balance	25,604	35,721
Related Allowance	852	3,982
Average Recorded Investment	24,507	39,555
Interest Income Recognized	403	2,191
Commercial real estate lending | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	17,367	28,399
Unpaid Principal Balance	18,160	29,243
Related Allowance	852	3,982
Average Recorded Investment	17,429	32,463
Interest Income Recognized	403	2,191
Commercial real estate lending | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	7,043	6,144
Unpaid Principal Balance	7,444	6,478
Related Allowance	0	0
Average Recorded Investment	7,078	7,092
Interest Income Recognized	0	0
Total commercial
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	243,610	264,832
Unpaid Principal Balance	262,119	296,304
Related Allowance	29,304	25,894
Average Recorded Investment	251,809	284,616
Interest Income Recognized	914	6,634
Total commercial | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	156,693	136,764
Unpaid Principal Balance	170,054	145,697
Related Allowance	29,304	25,894
Average Recorded Investment	162,835	150,785
Interest Income Recognized	821	4,977
Total commercial | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	86,917	128,068
Unpaid Principal Balance	92,065	150,607
Related Allowance	0	0
Average Recorded Investment	88,974	133,831
Interest Income Recognized	93	1,657
Residential mortgage
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	72,718	68,336
Unpaid Principal Balance	78,534	74,088
Related Allowance	11,860	11,091
Average Recorded Investment	73,002	70,435
Interest Income Recognized	656	2,447
Residential mortgage | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	66,221	62,362
Unpaid Principal Balance	71,013	67,090
Related Allowance	11,860	11,091
Average Recorded Investment	66,495	63,825
Interest Income Recognized	588	2,263
Residential mortgage | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	6,497	5,974
Unpaid Principal Balance	7,521	6,998
Related Allowance	0	0
Average Recorded Investment	6,507	6,610
Interest Income Recognized	68	184
Home equity
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	21,421	20,757
Unpaid Principal Balance	23,608	22,912
Related Allowance	9,528	9,312
Average Recorded Investment	21,611	21,932
Interest Income Recognized	250	1,118
Home equity | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	20,775	20,651
Unpaid Principal Balance	22,958	22,805
Related Allowance	9,528	9,312
Average Recorded Investment	20,964	21,825
Interest Income Recognized	250	1,114
Home equity | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	646	106
Unpaid Principal Balance	650	107
Related Allowance	0	0
Average Recorded Investment	647	107
Interest Income Recognized	0	4
Other consumer
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,301	1,235
Unpaid Principal Balance	1,327	1,284
Related Allowance	192	186
Average Recorded Investment	1,309	1,294
Interest Income Recognized	6	29
Other consumer | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,301	1,235
Unpaid Principal Balance	1,327	1,284
Related Allowance	192	186
Average Recorded Investment	1,309	1,294
Interest Income Recognized	6	29
Other consumer | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Total consumer
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	95,440	90,328
Unpaid Principal Balance	103,469	98,284
Related Allowance	21,580	20,589
Average Recorded Investment	95,922	93,661
Interest Income Recognized	912	3,594
Total consumer | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	88,297	84,248
Unpaid Principal Balance	95,298	91,179
Related Allowance	21,580	20,589
Average Recorded Investment	88,768	86,944
Interest Income Recognized	844	3,406
Total consumer | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	7,143	6,080
Unpaid Principal Balance	8,171	7,105
Related Allowance	0	0
Average Recorded Investment	7,154	6,717
Interest Income Recognized	$ 68	$ 188