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, 2019	Dec. 31, 2018
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	$ 159,763	$ 133,690
Unpaid Principal Balance	187,705	164,766
Related Allowance	20,684	15,304
Average Recorded Investment	119,935	145,707
Interest Income Recognized	$ 2,732	$ 3,626
Net Recorded Investment of the Impaired Loans	74.00%	72.00%
Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	$ 107,228	$ 96,609
Unpaid Principal Balance	115,307	102,483
Related Allowance	20,684	15,304
Average Recorded Investment	94,072	110,079
Interest Income Recognized	1,025	3,699
Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	52,535	37,081
Unpaid Principal Balance	72,399	62,283
Related Allowance	0	0
Average Recorded Investment	25,863	35,627
Interest Income Recognized	1,708	73
Commercial and industrial
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	87,798	63,153
Unpaid Principal Balance	109,873	87,155
Related Allowance	10,876	5,721
Average Recorded Investment	52,184	73,813
Interest Income Recognized	1,974	823
Commercial and industrial | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	44,810	40,747
Unpaid Principal Balance	48,448	42,131
Related Allowance	10,876	5,721
Average Recorded Investment	36,288	52,461
Interest Income Recognized	317	1,167
Commercial and industrial | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	42,988	22,406
Unpaid Principal Balance	61,425	45,024
Related Allowance	0	0
Average Recorded Investment	15,896	21,352
Interest Income Recognized	1,657	344
Commercial real estate — owner occupied
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	2,834	5,852
Unpaid Principal Balance	2,851	6,910
Related Allowance	50	24
Average Recorded Investment	2,122	6,154
Interest Income Recognized	30	104
Commercial real estate — owner occupied | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	2,104	2,080
Unpaid Principal Balance	2,111	2,087
Related Allowance	50	24
Average Recorded Investment	2,122	2,179
Interest Income Recognized	27	104
Commercial real estate — owner occupied | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	730	3,772
Unpaid Principal Balance	740	4,823
Related Allowance	0	0
Average Recorded Investment	0	3,975
Interest Income Recognized	3	0
Commercial and business lending
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	90,632	69,005
Unpaid Principal Balance	112,724	94,065
Related Allowance	10,926	5,745
Average Recorded Investment	54,307	79,967
Interest Income Recognized	2,004	927
Commercial and business lending | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	46,914	42,827
Unpaid Principal Balance	50,559	44,218
Related Allowance	10,926	5,745
Average Recorded Investment	38,411	54,640
Interest Income Recognized	344	1,271
Commercial and business lending | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	43,718	26,178
Unpaid Principal Balance	62,166	49,847
Related Allowance	0	0
Average Recorded Investment	15,896	25,327
Interest Income Recognized	1,660	344
Commercial real estate — investor
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	2,335	2,384
Unpaid Principal Balance	3,604	3,625
Related Allowance	26	28
Average Recorded Investment	2,351	1,807
Interest Income Recognized	17	106
Commercial real estate — investor | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	1,700	799
Unpaid Principal Balance	1,799	805
Related Allowance	26	28
Average Recorded Investment	792	827
Interest Income Recognized	17	38
Commercial real estate — investor | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	635	1,585
Unpaid Principal Balance	1,805	2,820
Related Allowance	0	0
Average Recorded Investment	1,559	980
Interest Income Recognized	0	68
Real estate construction
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	498	510
Unpaid Principal Balance	578	589
Related Allowance	69	75
Average Recorded Investment	502	533
Interest Income Recognized	9	32
Real estate construction | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	498	510
Unpaid Principal Balance	578	589
Related Allowance	69	75
Average Recorded Investment	502	533
Interest Income Recognized	9	32
Real estate construction | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
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
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	2,833	2,894
Unpaid Principal Balance	4,182	4,214
Related Allowance	94	103
Average Recorded Investment	2,852	2,340
Interest Income Recognized	25	138
Commercial real estate lending | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	2,198	1,309
Unpaid Principal Balance	2,377	1,394
Related Allowance	94	103
Average Recorded Investment	1,293	1,360
Interest Income Recognized	25	70
Commercial real estate lending | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	635	1,585
Unpaid Principal Balance	1,805	2,820
Related Allowance	0	0
Average Recorded Investment	1,559	980
Interest Income Recognized	0	68
Total commercial
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	93,465	71,899
Unpaid Principal Balance	116,906	98,279
Related Allowance	11,021	5,848
Average Recorded Investment	57,159	82,307
Interest Income Recognized	2,029	1,065
Total commercial | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	49,112	44,136
Unpaid Principal Balance	52,936	45,612
Related Allowance	11,021	5,848
Average Recorded Investment	39,704	56,000
Interest Income Recognized	369	1,341
Total commercial | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	44,353	27,763
Unpaid Principal Balance	63,970	52,667
Related Allowance	0	0
Average Recorded Investment	17,455	26,307
Interest Income Recognized	1,660	276
Residential mortgage
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	54,348	50,486
Unpaid Principal Balance	57,824	54,223
Related Allowance	6,197	6,023
Average Recorded Investment	51,079	51,477
Interest Income Recognized	574	1,992
Residential mortgage | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	46,165	41,691
Unpaid Principal Balance	49,395	45,149
Related Allowance	6,197	6,023
Average Recorded Investment	43,194	42,687
Interest Income Recognized	527	1,789
Residential mortgage | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	8,182	8,795
Unpaid Principal Balance	8,429	9,074
Related Allowance	0	0
Average Recorded Investment	7,885	8,790
Interest Income Recognized	48	203
Home equity
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	10,792	10,124
Unpaid Principal Balance	11,815	11,081
Related Allowance	3,348	3,312
Average Recorded Investment	10,538	10,739
Interest Income Recognized	128	566
Home equity | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	10,792	9,601
Unpaid Principal Balance	11,815	10,539
Related Allowance	3,348	3,312
Average Recorded Investment	10,015	10,209
Interest Income Recognized	128	566
Home equity | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	0	523
Unpaid Principal Balance	0	542
Related Allowance	0	0
Average Recorded Investment	523	530
Interest Income Recognized	0	0
Other consumer
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	1,158	1,181
Unpaid Principal Balance	1,161	1,183
Related Allowance	119	121
Average Recorded Investment	1,159	1,184
Interest Income Recognized	0	3
Other consumer | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	1,158	1,181
Unpaid Principal Balance	1,161	1,183
Related Allowance	119	121
Average Recorded Investment	1,159	1,184
Interest Income Recognized	0	3
Other consumer | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
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
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	66,298	61,791
Unpaid Principal Balance	70,799	66,487
Related Allowance	9,664	9,456
Average Recorded Investment	62,776	63,400
Interest Income Recognized	703	2,561
Total consumer | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	58,116	52,473
Unpaid Principal Balance	62,370	56,871
Related Allowance	9,664	9,456
Average Recorded Investment	54,368	54,080
Interest Income Recognized	655	2,358
Total consumer | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Recorded Investment	8,182	9,318
Unpaid Principal Balance	8,429	9,616
Related Allowance	0	0
Average Recorded Investment	8,408	9,320
Interest Income Recognized	$ 48	$ 203