Loans, Impaired Loans Recorded Investment, Unpaid Principal Balance, Related Allowance, Average Recorded Investment, and Interest Income Recognized (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 309,213	$ 355,160
Unpaid Principal Balance	349,590	394,588
Related Allowance	39,988	46,483
Average Recorded Investment	336,528	378,277
Interest Income Recognized	$ 3,480	$ 10,228
Net Recorded Investment of the Impaired Loans	77.00%	78.00%
Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 196,914	$ 221,012
Unpaid Principal Balance	211,096	236,876
Related Allowance	39,988	46,483
Average Recorded Investment	202,339	237,729
Interest Income Recognized	3,157	8,383
Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	112,299	134,148
Unpaid Principal Balance	138,494	157,712
Related Allowance	0	0
Average Recorded Investment	134,189	140,548
Interest Income Recognized	323	1,845
Commercial and industrial
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	173,015	215,255
Unpaid Principal Balance	201,702	242,676
Related Allowance	17,882	21,617
Average Recorded Investment	200,194	229,191
Interest Income Recognized	808	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	89,563	101,770
Unpaid Principal Balance	94,231	107,813
Related Allowance	17,882	21,617
Average Recorded Investment	95,205	111,211
Interest Income Recognized	635	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	83,452	113,485
Unpaid Principal Balance	107,471	134,863
Related Allowance	0	0
Average Recorded Investment	104,989	117,980
Interest Income Recognized	173	1,519
Commercial real estate — owner occupied
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	19,945	15,034
Unpaid Principal Balance	22,700	17,907
Related Allowance	526	295
Average Recorded Investment	18,992	15,870
Interest Income Recognized	142	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	7,249	6,595
Unpaid Principal Balance	9,154	8,641
Related Allowance	526	295
Average Recorded Investment	6,086	7,111
Interest Income Recognized	93	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	12,696	8,439
Unpaid Principal Balance	13,546	9,266
Related Allowance	0	0
Average Recorded Investment	12,906	8,759
Interest Income Recognized	49	138
Commercial and business lending
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	192,960	230,289
Unpaid Principal Balance	224,402	260,583
Related Allowance	18,408	21,912
Average Recorded Investment	219,186	245,061
Interest Income Recognized	950	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	96,812	108,365
Unpaid Principal Balance	103,385	116,454
Related Allowance	18,408	21,912
Average Recorded Investment	101,291	118,322
Interest Income Recognized	728	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	96,148	121,924
Unpaid Principal Balance	121,017	144,129
Related Allowance	0	0
Average Recorded Investment	117,895	126,739
Interest Income Recognized	222	1,657
Commercial real estate — investor
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	21,834	33,340
Unpaid Principal Balance	22,577	34,155
Related Allowance	330	3,541
Average Recorded Investment	21,853	38,234
Interest Income Recognized	767	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	15,832	27,196
Unpaid Principal Balance	16,111	27,677
Related Allowance	330	3,541
Average Recorded Investment	15,782	31,142
Interest Income Recognized	767	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	6,002	6,144
Unpaid Principal Balance	6,466	6,478
Related Allowance	0	0
Average Recorded Investment	6,071	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	2,038	1,203
Unpaid Principal Balance	2,410	1,566
Related Allowance	707	441
Average Recorded Investment	2,090	1,321
Interest Income Recognized	54	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	1,819	1,203
Unpaid Principal Balance	2,188	1,566
Related Allowance	707	441
Average Recorded Investment	1,868	1,321
Interest Income Recognized	54	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	219	0
Unpaid Principal Balance	222	0
Related Allowance	0	0
Average Recorded Investment	222	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	23,872	34,543
Unpaid Principal Balance	24,987	35,721
Related Allowance	1,037	3,982
Average Recorded Investment	23,943	39,555
Interest Income Recognized	821	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	17,651	28,399
Unpaid Principal Balance	18,299	29,243
Related Allowance	1,037	3,982
Average Recorded Investment	17,650	32,463
Interest Income Recognized	821	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	6,221	6,144
Unpaid Principal Balance	6,688	6,478
Related Allowance	0	0
Average Recorded Investment	6,293	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	216,832	264,832
Unpaid Principal Balance	249,389	296,304
Related Allowance	19,445	25,894
Average Recorded Investment	243,129	284,616
Interest Income Recognized	1,771	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	114,463	136,764
Unpaid Principal Balance	121,684	145,697
Related Allowance	19,445	25,894
Average Recorded Investment	118,941	150,785
Interest Income Recognized	1,549	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	102,369	128,068
Unpaid Principal Balance	127,705	150,607
Related Allowance	0	0
Average Recorded Investment	124,188	133,831
Interest Income Recognized	222	1,657
Residential mortgage
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	69,599	68,336
Unpaid Principal Balance	75,409	74,088
Related Allowance	10,649	11,091
Average Recorded Investment	70,292	70,435
Interest Income Recognized	1,213	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	60,209	62,362
Unpaid Principal Balance	65,163	67,090
Related Allowance	10,649	11,091
Average Recorded Investment	60,831	63,825
Interest Income Recognized	1,112	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	9,390	5,974
Unpaid Principal Balance	10,246	6,998
Related Allowance	0	0
Average Recorded Investment	9,461	6,610
Interest Income Recognized	101	184
Home equity
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	21,467	20,757
Unpaid Principal Balance	23,450	22,912
Related Allowance	9,665	9,312
Average Recorded Investment	21,772	21,932
Interest Income Recognized	484	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	20,927	20,651
Unpaid Principal Balance	22,907	22,805
Related Allowance	9,665	9,312
Average Recorded Investment	21,232	21,825
Interest Income Recognized	484	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	540	106
Unpaid Principal Balance	543	107
Related Allowance	0	0
Average Recorded Investment	540	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	1,315	1,235
Unpaid Principal Balance	1,342	1,284
Related Allowance	229	186
Average Recorded Investment	1,335	1,294
Interest Income Recognized	12	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	1,315	1,235
Unpaid Principal Balance	1,342	1,284
Related Allowance	229	186
Average Recorded Investment	1,335	1,294
Interest Income Recognized	12	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	92,381	90,328
Unpaid Principal Balance	100,201	98,284
Related Allowance	20,543	20,589
Average Recorded Investment	93,399	93,661
Interest Income Recognized	1,709	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	82,451	84,248
Unpaid Principal Balance	89,412	91,179
Related Allowance	20,543	20,589
Average Recorded Investment	83,398	86,944
Interest Income Recognized	1,608	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	9,930	6,080
Unpaid Principal Balance	10,789	7,105
Related Allowance	0	0
Average Recorded Investment	10,001	6,717
Interest Income Recognized	$ 101	$ 188