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, 2016	Dec. 31, 2015
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 371,992	$ 265,621
Unpaid Principal Balance	395,678	284,433
Related Allowance	39,109	33,669
Average Recorded Investment	373,687	273,011
Interest Income Recognized	$ 2,117	$ 8,716
Net Recorded Investment of the Impaired Loans	84.00%	82.00%
Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 227,871	$ 186,275
Unpaid Principal Balance	238,082	197,109
Related Allowance	39,109	33,669
Average Recorded Investment	229,224	178,871
Interest Income Recognized	1,981	6,798
Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	144,121	79,346
Unpaid Principal Balance	157,596	87,324
Related Allowance	0	0
Average Recorded Investment	144,463	94,140
Interest Income Recognized	136	1,918
Commercial and industrial
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	226,023	122,868
Unpaid Principal Balance	237,772	131,668
Related Allowance	14,595	8,162
Average Recorded Investment	226,679	126,406
Interest Income Recognized	704	2,512
Commercial and industrial | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	105,780	57,785
Unpaid Principal Balance	106,837	59,409
Related Allowance	14,595	8,162
Average Recorded Investment	106,280	46,833
Interest Income Recognized	613	855
Commercial and industrial | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	120,243	65,083
Unpaid Principal Balance	130,935	72,259
Related Allowance	0	0
Average Recorded Investment	120,399	79,573
Interest Income Recognized	91	1,657
Commercial real estate — owner occupied
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	17,136	15,926
Unpaid Principal Balance	19,601	16,452
Related Allowance	554	448
Average Recorded Investment	17,267	16,621
Interest Income Recognized	89	427
Commercial real estate — owner occupied | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	10,477	9,705
Unpaid Principal Balance	10,596	9,804
Related Allowance	554	448
Average Recorded Investment	10,552	10,087
Interest Income Recognized	89	412
Commercial real estate — owner occupied | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	6,659	6,221
Unpaid Principal Balance	9,005	6,648
Related Allowance	0	0
Average Recorded Investment	6,715	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	243,159	138,794
Unpaid Principal Balance	257,373	148,120
Related Allowance	15,149	8,610
Average Recorded Investment	243,946	143,027
Interest Income Recognized	793	2,939
Commercial and business lending | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	116,257	67,490
Unpaid Principal Balance	117,433	69,213
Related Allowance	15,149	8,610
Average Recorded Investment	116,832	56,920
Interest Income Recognized	702	1,267
Commercial and business lending | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	126,902	71,304
Unpaid Principal Balance	139,940	78,907
Related Allowance	0	0
Average Recorded Investment	127,114	86,107
Interest Income Recognized	91	1,672
Commercial real estate — investor
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	33,323	30,558
Unpaid Principal Balance	34,414	32,284
Related Allowance	1,244	1,831
Average Recorded Investment	33,396	31,041
Interest Income Recognized	461	2,004
Commercial real estate — investor | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	23,494	27,822
Unpaid Principal Balance	24,430	29,444
Related Allowance	1,244	1,831
Average Recorded Investment	23,541	28,278
Interest Income Recognized	461	1,914
Commercial real estate — investor | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	9,829	2,736
Unpaid Principal Balance	9,984	2,840
Related Allowance	0	0
Average Recorded Investment	9,855	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	1,226	1,450
Unpaid Principal Balance	1,812	2,154
Related Allowance	412	453
Average Recorded Investment	1,237	1,667
Interest Income Recognized	14	66
Real estate construction | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,226	1,450
Unpaid Principal Balance	1,812	2,154
Related Allowance	412	453
Average Recorded Investment	1,237	1,667
Interest Income Recognized	14	66
Real estate construction | Loans With No Related Allowance [Member]
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 [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	34,549	32,008
Unpaid Principal Balance	36,226	34,438
Related Allowance	1,656	2,284
Average Recorded Investment	34,633	32,708
Interest Income Recognized	475	2,070
Commercial Real Estate Lending [Member] | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	24,720	29,272
Unpaid Principal Balance	26,242	31,598
Related Allowance	1,656	2,284
Average Recorded Investment	24,778	29,945
Interest Income Recognized	475	1,980
Commercial Real Estate Lending [Member] | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	9,829	2,736
Unpaid Principal Balance	9,984	2,840
Related Allowance	0	0
Average Recorded Investment	9,855	2,763
Interest Income Recognized	0	90
Commercial Financing Receivable [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	277,708	170,802
Unpaid Principal Balance	293,599	182,558
Related Allowance	16,805	10,894
Average Recorded Investment	278,579	175,735
Interest Income Recognized	1,268	5,009
Commercial Financing Receivable [Member] | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	140,977	96,762
Unpaid Principal Balance	143,675	100,811
Related Allowance	16,805	10,894
Average Recorded Investment	141,610	86,865
Interest Income Recognized	1,177	3,247
Commercial Financing Receivable [Member] | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	136,731	74,040
Unpaid Principal Balance	149,924	81,747
Related Allowance	0	0
Average Recorded Investment	136,969	88,870
Interest Income Recognized	91	1,762
Residential mortgage
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	72,019	71,352
Unpaid Principal Balance	77,644	76,117
Related Allowance	12,351	12,462
Average Recorded Investment	72,660	72,909
Interest Income Recognized	583	2,500
Residential mortgage | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	65,281	66,590
Unpaid Principal Balance	70,624	71,084
Related Allowance	12,351	12,462
Average Recorded Investment	65,819	68,183
Interest Income Recognized	548	2,374
Residential mortgage | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	6,738	4,762
Unpaid Principal Balance	7,020	5,033
Related Allowance	0	0
Average Recorded Investment	6,841	4,726
Interest Income Recognized	35	126
Home equity
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	20,989	22,313
Unpaid Principal Balance	23,103	24,533
Related Allowance	9,732	10,118
Average Recorded Investment	21,157	23,168
Interest Income Recognized	258	1,177
Home equity | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	20,337	21,769
Unpaid Principal Balance	22,451	23,989
Related Allowance	9,732	10,118
Average Recorded Investment	20,504	22,624
Interest Income Recognized	248	1,147
Home equity | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	652	544
Unpaid Principal Balance	652	544
Related Allowance	0	0
Average Recorded Investment	653	544
Interest Income Recognized	10	30
Other consumer
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,276	1,154
Unpaid Principal Balance	1,332	1,225
Related Allowance	221	195
Average Recorded Investment	1,291	1,199
Interest Income Recognized	8	30
Other consumer | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,276	1,154
Unpaid Principal Balance	1,332	1,225
Related Allowance	221	195
Average Recorded Investment	1,291	1,199
Interest Income Recognized	8	30
Other consumer | Loans With No Related Allowance [Member]
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
Consumer Loan [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	94,284	94,819
Unpaid Principal Balance	102,079	101,875
Related Allowance	22,304	22,775
Average Recorded Investment	95,108	97,276
Interest Income Recognized	849	3,707
Consumer Loan [Member] | Loans With Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	86,894	89,513
Unpaid Principal Balance	94,407	96,298
Related Allowance	22,304	22,775
Average Recorded Investment	87,614	92,006
Interest Income Recognized	804	3,551
Consumer Loan [Member] | Loans With No Related Allowance [Member]
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	7,390	5,306
Unpaid Principal Balance	7,672	5,577
Related Allowance	0	0
Average Recorded Investment	7,494	5,270
Interest Income Recognized	$ 45	$ 156