Loans, Impaired Loans Recorded Investment, Unpaid Principal Balance, Related Allowance, Average Recorded Investment, and Interest Income Recognized (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 369,981	$ 265,621
Unpaid Principal Balance	431,712	284,433
Related Allowance	33,150	33,669
Average Recorded Investment	383,840	273,011
Interest Income Recognized	$ 6,945	$ 8,716
Net Recorded Investment of the Impaired Loans	78.00%	82.00%
Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 176,312	$ 186,275
Unpaid Principal Balance	190,587	197,109
Related Allowance	33,150	33,669
Average Recorded Investment	183,988	178,871
Interest Income Recognized	5,562	6,798
Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	193,669	79,346
Unpaid Principal Balance	241,125	87,324
Related Allowance	0	0
Average Recorded Investment	199,852	94,140
Interest Income Recognized	1,383	1,918
Commercial and industrial
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	236,150	122,868
Unpaid Principal Balance	286,799	131,668
Related Allowance	9,293	8,162
Average Recorded Investment	241,033	126,406
Interest Income Recognized	2,455	2,512
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	61,219	57,785
Unpaid Principal Balance	65,586	59,409
Related Allowance	9,293	8,162
Average Recorded Investment	61,337	46,833
Interest Income Recognized	1,228	855
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	174,931	65,083
Unpaid Principal Balance	221,213	72,259
Related Allowance	0	0
Average Recorded Investment	179,696	79,573
Interest Income Recognized	1,227	1,657
Commercial real estate — owner occupied
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	14,440	15,926
Unpaid Principal Balance	17,113	16,452
Related Allowance	319	448
Average Recorded Investment	15,039	16,621
Interest Income Recognized	262	427
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	8,721	9,705
Unpaid Principal Balance	10,641	9,804
Related Allowance	319	448
Average Recorded Investment	9,133	10,087
Interest Income Recognized	262	412
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	5,719	6,221
Unpaid Principal Balance	6,472	6,648
Related Allowance	0	0
Average Recorded Investment	5,906	6,534
Interest Income Recognized	0	15
Commercial and business lending
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	250,590	138,794
Unpaid Principal Balance	303,912	148,120
Related Allowance	9,612	8,610
Average Recorded Investment	256,072	143,027
Interest Income Recognized	2,717	2,939
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	69,940	67,490
Unpaid Principal Balance	76,227	69,213
Related Allowance	9,612	8,610
Average Recorded Investment	70,470	56,920
Interest Income Recognized	1,490	1,267
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	180,650	71,304
Unpaid Principal Balance	227,685	78,907
Related Allowance	0	0
Average Recorded Investment	185,602	86,107
Interest Income Recognized	1,227	1,672
Commercial real estate — investor
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	23,380	30,558
Unpaid Principal Balance	24,102	32,284
Related Allowance	629	1,831
Average Recorded Investment	28,843	31,041
Interest Income Recognized	1,405	2,004
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	17,154	27,822
Unpaid Principal Balance	17,601	29,444
Related Allowance	629	1,831
Average Recorded Investment	21,450	28,278
Interest Income Recognized	1,405	1,914
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	6,226	2,736
Unpaid Principal Balance	6,501	2,840
Related Allowance	0	0
Average Recorded Investment	7,393	2,763
Interest Income Recognized	0	90
Real estate construction
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,229	1,450
Unpaid Principal Balance	1,626	2,154
Related Allowance	449	453
Average Recorded Investment	1,301	1,667
Interest Income Recognized	49	66
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	1,229	1,450
Unpaid Principal Balance	1,626	2,154
Related Allowance	449	453
Average Recorded Investment	1,301	1,667
Interest Income Recognized	49	66
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	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	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	24,609	32,008
Unpaid Principal Balance	25,728	34,438
Related Allowance	1,078	2,284
Average Recorded Investment	30,144	32,708
Interest Income Recognized	1,454	2,070
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	18,383	29,272
Unpaid Principal Balance	19,227	31,598
Related Allowance	1,078	2,284
Average Recorded Investment	22,751	29,945
Interest Income Recognized	1,454	1,980
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	6,226	2,736
Unpaid Principal Balance	6,501	2,840
Related Allowance	0	0
Average Recorded Investment	7,393	2,763
Interest Income Recognized	0	90
Total commercial
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	275,199	170,802
Unpaid Principal Balance	329,640	182,558
Related Allowance	10,690	10,894
Average Recorded Investment	286,216	175,735
Interest Income Recognized	4,171	5,009
Total commercial | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	88,323	96,762
Unpaid Principal Balance	95,454	100,811
Related Allowance	10,690	10,894
Average Recorded Investment	93,221	86,865
Interest Income Recognized	2,944	3,247
Total commercial | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	186,876	74,040
Unpaid Principal Balance	234,186	81,747
Related Allowance	0	0
Average Recorded Investment	192,995	88,870
Interest Income Recognized	1,227	1,762
Residential mortgage
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	71,524	71,352
Unpaid Principal Balance	76,857	76,117
Related Allowance	12,087	12,462
Average Recorded Investment	73,051	72,909
Interest Income Recognized	1,867	2,500
Residential mortgage | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	65,381	66,590
Unpaid Principal Balance	70,568	71,084
Related Allowance	12,087	12,462
Average Recorded Investment	66,845	68,183
Interest Income Recognized	1,734	2,374
Residential mortgage | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	6,143	4,762
Unpaid Principal Balance	6,289	5,033
Related Allowance	0	0
Average Recorded Investment	6,206	4,726
Interest Income Recognized	133	126
Home equity
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	22,032	22,313
Unpaid Principal Balance	23,927	24,533
Related Allowance	10,162	10,118
Average Recorded Investment	23,305	23,168
Interest Income Recognized	885	1,177
Home equity | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	21,382	21,769
Unpaid Principal Balance	23,277	23,989
Related Allowance	10,162	10,118
Average Recorded Investment	22,654	22,624
Interest Income Recognized	862	1,147
Home equity | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	650	544
Unpaid Principal Balance	650	544
Related Allowance	0	0
Average Recorded Investment	651	544
Interest Income Recognized	23	30
Other consumer
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,226	1,154
Unpaid Principal Balance	1,288	1,225
Related Allowance	211	195
Average Recorded Investment	1,268	1,199
Interest Income Recognized	22	30
Other consumer | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,226	1,154
Unpaid Principal Balance	1,288	1,225
Related Allowance	211	195
Average Recorded Investment	1,268	1,199
Interest Income Recognized	22	30
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	94,782	94,819
Unpaid Principal Balance	102,072	101,875
Related Allowance	22,460	22,775
Average Recorded Investment	97,624	97,276
Interest Income Recognized	2,774	3,707
Total consumer | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	87,989	89,513
Unpaid Principal Balance	95,133	96,298
Related Allowance	22,460	22,775
Average Recorded Investment	90,767	92,006
Interest Income Recognized	2,618	3,551
Total consumer | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	6,793	5,306
Unpaid Principal Balance	6,939	5,577
Related Allowance	0	0
Average Recorded Investment	6,857	5,270
Interest Income Recognized	$ 156	$ 156