Loans and Leases and Allowance for Credit Losses Loans and Leases and Allowance for Credit Losses - Amortized cost of loans by risk category by vintage year (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 784,229
2019	2,264,976
2018	1,670,838
2017	1,095,439
2016	888,616
Prior	963,926
Revolvers	1,176,292
Revolvers converted to term loans	91,108
Total	8,935,424	$ 8,812,553
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	755,531
2019	2,203,978
2018	1,640,836
2017	1,057,369
2016	862,130
Prior	934,832
Revolvers	1,134,975
Revolvers converted to term loans	81,481
Total	8,671,132	8,558,459
Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	12,639
2019	23,408
2018	17,770
2017	16,330
2016	17,576
Prior	8,077
Revolvers	16,989
Revolvers converted to term loans	2,024
Total	114,813	93,703
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	16,059
2019	37,590
2018	12,232
2017	21,740
2016	8,910
Prior	21,017
Revolvers	24,328
Revolvers converted to term loans	7,603
Total	149,479	$ 160,391
Commercial | Owner occupied commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	116,307
2019	419,829
2018	278,715
2017	260,143
2016	233,929
Prior	300,688
Revolvers	64,536
Revolvers converted to term loans	28,837
Total	1,702,984
Commercial | Owner occupied commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	108,385
2019	402,541
2018	271,646
2017	236,178
2016	222,321
Prior	287,441
Revolvers	60,479
Revolvers converted to term loans	28,008
Total	1,616,999
Commercial | Owner occupied commercial real estate | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	4,602
2019	8,706
2018	4,166
2017	11,315
2016	7,869
Prior	4,634
Revolvers	842
Revolvers converted to term loans	70
Total	42,204
Commercial | Owner occupied commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,320
2019	8,582
2018	2,903
2017	12,650
2016	3,739
Prior	8,613
Revolvers	3,215
Revolvers converted to term loans	759
Total	43,781
Commercial | Income producing commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	223,962
2019	527,256
2018	412,125
2017	292,590
2016	295,604
Prior	264,171
Revolvers	37,060
Revolvers converted to term loans	11,734
Total	2,064,502
Commercial | Income producing commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	206,665
2019	500,411
2018	399,578
2017	284,259
2016	286,601
Prior	258,605
Revolvers	37,060
Revolvers converted to term loans	9,820
Total	1,982,999
Commercial | Income producing commercial real estate | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	6,665
2019	12,955
2018	9,885
2017	4,214
2016	8,775
Prior	2,989
Revolvers	0
Revolvers converted to term loans	1,807
Total	47,290
Commercial | Income producing commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	10,632
2019	13,890
2018	2,662
2017	4,117
2016	228
Prior	2,577
Revolvers	0
Revolvers converted to term loans	107
Total	34,213
Commercial | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	88,371
2019	277,318
2018	244,814
2017	128,798
2016	97,051
Prior	64,809
Revolvers	398,355
Revolvers converted to term loans	10,596
Total	1,310,112
Commercial | Commercial & industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	87,261
2019	267,166
2018	240,535
2017	125,838
2016	93,442
Prior	63,150
Revolvers	361,419
Revolvers converted to term loans	9,674
Total	1,248,485
Commercial | Commercial & industrial | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,066
2019	807
2018	2,725
2017	620
2016	883
Prior	53
Revolvers	16,140
Revolvers converted to term loans	147
Total	22,441
Commercial | Commercial & industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	44
2019	9,345
2018	1,554
2017	2,340
2016	2,726
Prior	1,606
Revolvers	20,796
Revolvers converted to term loans	775
Total	39,186
Commercial | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2020	92,066
2019	249,884
2018	315,528
2017	163,601
2016	92,829
Prior	20,815
Revolvers	15,565
Revolvers converted to term loans	9,030
Total	959,318
Commercial | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	90,555
2019	246,335
2018	313,984
2017	163,033
2016	91,830
Prior	19,976
Revolvers	15,565
Revolvers converted to term loans	7,600
Total	948,878
Commercial | Construction | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	306
2019	940
2018	994
2017	181
2016	49
Prior	401
Revolvers	0
Revolvers converted to term loans	0
Total	2,871
Commercial | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,205
2019	2,609
2018	550
2017	387
2016	950
Prior	438
Revolvers	0
Revolvers converted to term loans	1,430
Total	7,569
Commercial | Equipment financing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	124,870
2019	354,258
2018	188,787
2017	67,906
2016	21,557
Prior	3,574
Revolvers	0
Revolvers converted to term loans	0
Total	760,952
Commercial | Equipment financing | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	124,870
2019	353,441
2018	187,366
2017	67,279
2016	21,377
Prior	3,510
Revolvers	0
Revolvers converted to term loans	0
Total	757,843
Commercial | Equipment financing | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	817
2018	1,421
2017	627
2016	180
Prior	64
Revolvers	0
Revolvers converted to term loans	0
Total	3,109
Residential | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2020	34,849
2019	137,205
2018	13,736
2017	5,936
2016	5,298
Prior	18,810
Revolvers	0
Revolvers converted to term loans	162
Total	215,996
Residential | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	34,849
2019	137,032
2018	13,603
2017	5,911
2016	5,171
Prior	18,480
Revolvers	0
Revolvers converted to term loans	162
Total	215,208
Residential | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	173
2018	133
2017	25
2016	127
Prior	330
Revolvers	0
Revolvers converted to term loans	0
Total	788
Residential | Residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
2020	86,900
2019	253,260
2018	191,134
2017	166,174
2016	135,080
Prior	287,060
Revolvers	11
Revolvers converted to term loans	8,369
Total	1,127,988
Residential | Residential mortgage | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	86,068
2019	251,157
2018	188,207
2017	164,654
2016	134,189
Prior	279,723
Revolvers	11
Revolvers converted to term loans	8,009
Total	1,112,018
Residential | Residential mortgage | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	832
2019	2,103
2018	2,927
2017	1,520
2016	891
Prior	7,337
Revolvers	0
Revolvers converted to term loans	360
Total	15,970
Residential | Home equity lines of credit
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolvers	646,100
Revolvers converted to term loans	22,282
Total	668,382
Residential | Home equity lines of credit | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolvers	645,874
Revolvers converted to term loans	18,111
Total	663,985
Residential | Home equity lines of credit | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolvers	226
Revolvers converted to term loans	4,171
Total	4,397
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	16,904
2019	45,966
2018	25,999
2017	10,291
2016	7,268
Prior	3,999
Revolvers	14,665
Revolvers converted to term loans	98
Total	125,190
Consumer | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	16,878
2019	45,895
2018	25,917
2017	10,217
2016	7,199
Prior	3,947
Revolvers	14,567
Revolvers converted to term loans	97
Total	124,717
Consumer | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolvers	7
Revolvers converted to term loans	0
Total	7
Consumer | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	26
2019	71
2018	82
2017	74
2016	69
Prior	52
Revolvers	91
Revolvers converted to term loans	1
Total	$ 466