Loans, Impaired Loans Recorded Investment, Unpaid Principal Balance, Related Allowance, Average Recorded Investment, and Interest Income Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 133,690	$ 247,575
Unpaid Principal Balance	164,766	275,814
Related Allowance	15,304	25,846
Average Recorded Investment	145,707	236,860
Interest Income Recognized	$ 3,626	$ 8,051
Net Recorded Investment of the Impaired Loans	72.00%	80.00%
Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	$ 96,609	$ 175,681
Unpaid Principal Balance	102,483	181,002
Related Allowance	15,304	25,846
Average Recorded Investment	110,079	140,098
Interest Income Recognized	3,699	7,254
Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	37,081	71,894
Unpaid Principal Balance	62,283	94,812
Related Allowance	0	0
Average Recorded Investment	35,627	96,762
Interest Income Recognized	73	797
Commercial and industrial
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	63,153	142,244
Unpaid Principal Balance	87,155	166,418
Related Allowance	5,721	10,838
Average Recorded Investment	73,813	147,769
Interest Income Recognized	823	3,121
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	40,747	81,649
Unpaid Principal Balance	42,131	83,579
Related Allowance	5,721	10,838
Average Recorded Investment	52,461	58,494
Interest Income Recognized	1,167	2,629
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	22,406	60,595
Unpaid Principal Balance	45,024	82,839
Related Allowance	0	0
Average Recorded Investment	21,352	89,275
Interest Income Recognized	344	492
Commercial real estate — owner occupied
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	5,852	26,234
Unpaid Principal Balance	6,910	26,766
Related Allowance	24	2,973
Average Recorded Investment	6,154	14,072
Interest Income Recognized	104	772
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	2,080	23,796
Unpaid Principal Balance	2,087	23,937
Related Allowance	24	2,973
Average Recorded Investment	2,179	12,124
Interest Income Recognized	104	736
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	3,772	2,438
Unpaid Principal Balance	4,823	2,829
Related Allowance	0	0
Average Recorded Investment	3,975	1,948
Interest Income Recognized	0	36
Commercial and business lending
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	69,005	168,478
Unpaid Principal Balance	94,065	193,184
Related Allowance	5,745	13,811
Average Recorded Investment	79,967	161,841
Interest Income Recognized	927	3,893
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	42,827	105,445
Unpaid Principal Balance	44,218	107,516
Related Allowance	5,745	13,811
Average Recorded Investment	54,640	70,618
Interest Income Recognized	1,271	3,365
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	26,178	63,033
Unpaid Principal Balance	49,847	85,668
Related Allowance	0	0
Average Recorded Investment	25,327	91,223
Interest Income Recognized	344	528
Commercial real estate — investor
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	2,384	19,118
Unpaid Principal Balance	3,625	19,157
Related Allowance	28	1,597
Average Recorded Investment	1,807	16,924
Interest Income Recognized	106	1,739
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	799	17,823
Unpaid Principal Balance	805	17,862
Related Allowance	28	1,597
Average Recorded Investment	827	16,924
Interest Income Recognized	38	1,694
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	1,585	1,295
Unpaid Principal Balance	2,820	1,295
Related Allowance	0	0
Average Recorded Investment	980	0
Interest Income Recognized	68	45
Real estate construction
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	510	467
Unpaid Principal Balance	589	578
Related Allowance	75	86
Average Recorded Investment	533	484
Interest Income Recognized	32	29
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	510	467
Unpaid Principal Balance	589	578
Related Allowance	75	86
Average Recorded Investment	533	484
Interest Income Recognized	32	29
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	2,894	19,585
Unpaid Principal Balance	4,214	19,735
Related Allowance	103	1,683
Average Recorded Investment	2,340	17,408
Interest Income Recognized	138	1,768
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	1,309	18,290
Unpaid Principal Balance	1,394	18,440
Related Allowance	103	1,683
Average Recorded Investment	1,360	17,408
Interest Income Recognized	70	1,723
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	1,585	1,295
Unpaid Principal Balance	2,820	1,295
Related Allowance	0	0
Average Recorded Investment	980	0
Interest Income Recognized	68	45
Total commercial
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	71,899	188,063
Unpaid Principal Balance	98,279	212,919
Related Allowance	5,848	15,494
Average Recorded Investment	82,307	179,249
Interest Income Recognized	1,065	5,661
Total commercial | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	44,136	123,735
Unpaid Principal Balance	45,612	125,956
Related Allowance	5,848	15,494
Average Recorded Investment	56,000	88,026
Interest Income Recognized	1,341	5,088
Total commercial | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	27,763	64,328
Unpaid Principal Balance	52,667	86,963
Related Allowance	0	0
Average Recorded Investment	26,307	91,223
Interest Income Recognized	276	573
Residential mortgage
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	50,486	47,486
Unpaid Principal Balance	54,223	50,126
Related Allowance	6,023	6,512
Average Recorded Investment	51,477	45,410
Interest Income Recognized	1,992	1,831
Residential mortgage | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	41,691	40,561
Unpaid Principal Balance	45,149	42,922
Related Allowance	6,023	6,512
Average Recorded Investment	42,687	40,411
Interest Income Recognized	1,789	1,614
Residential mortgage | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	8,795	6,925
Unpaid Principal Balance	9,074	7,204
Related Allowance	0	0
Average Recorded Investment	8,790	4,999
Interest Income Recognized	203	217
Home equity
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	10,124	10,891
Unpaid Principal Balance	11,081	11,631
Related Allowance	3,312	3,718
Average Recorded Investment	10,739	11,061
Interest Income Recognized	566	556
Home equity | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	9,601	10,250
Unpaid Principal Balance	10,539	10,986
Related Allowance	3,312	3,718
Average Recorded Investment	10,209	10,521
Interest Income Recognized	566	549
Home equity | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	523	641
Unpaid Principal Balance	542	645
Related Allowance	0	0
Average Recorded Investment	530	540
Interest Income Recognized	0	7
Other consumer
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,181	1,135
Unpaid Principal Balance	1,183	1,138
Related Allowance	121	122
Average Recorded Investment	1,184	1,140
Interest Income Recognized	3	3
Other consumer | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	1,181	1,135
Unpaid Principal Balance	1,183	1,138
Related Allowance	121	122
Average Recorded Investment	1,184	1,140
Interest Income Recognized	3	3
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	61,791	59,512
Unpaid Principal Balance	66,487	62,895
Related Allowance	9,456	10,352
Average Recorded Investment	63,400	57,611
Interest Income Recognized	2,561	2,390
Total consumer | Loans with a related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	52,473	51,946
Unpaid Principal Balance	56,871	55,046
Related Allowance	9,456	10,352
Average Recorded Investment	54,080	52,072
Interest Income Recognized	2,358	2,166
Total consumer | Loans with no related allowance
Summarize of nonaccrual loans, accruing loans past due 90 days or more, and restructured loans
Recorded Investment	9,318	7,566
Unpaid Principal Balance	9,616	7,849
Related Allowance	0	0
Average Recorded Investment	9,320	5,539
Interest Income Recognized	$ 203	$ 224