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	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 3,965,998
2019	2,164,164
2018	1,639,789
2017	976,227
2016	837,937
Prior	816,260
Revolvers	1,329,843
Revolvers converted to term loans	68,692
Total	11,798,910	$ 8,812,553
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,908,849
2019	2,129,948
2018	1,589,733
2017	933,825
2016	779,683
Prior	779,596
Revolvers	1,300,519
Revolvers converted to term loans	59,706
Total	11,481,859	8,558,459
Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	29,479
2019	10,436
2018	21,812
2017	17,757
2016	35,281
Prior	14,639
Revolvers	11,168
Revolvers converted to term loans	1,908
Total	142,480	93,703
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	27,670
2019	23,780
2018	28,244
2017	24,645
2016	22,973
Prior	22,025
Revolvers	18,156
Revolvers converted to term loans	7,078
Total	174,571	$ 160,391
Commercial | Owner occupied commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	546,704
2019	420,141
2018	267,968
2017	236,139
2016	227,317
Prior	240,616
Revolvers	57,284
Revolvers converted to term loans	12,505
Total	2,008,674
Commercial | Owner occupied commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	536,362
2019	407,134
2018	258,280
2017	218,505
2016	213,644
Prior	228,141
Revolvers	54,615
Revolvers converted to term loans	11,174
Total	1,927,855
Commercial | Owner occupied commercial real estate | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	4,552
2019	4,916
2018	1,019
2017	3,987
2016	11,021
Prior	3,719
Revolvers	620
Revolvers converted to term loans	59
Total	29,893
Commercial | Owner occupied commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	5,790
2019	8,091
2018	8,669
2017	13,647
2016	2,652
Prior	8,756
Revolvers	2,049
Revolvers converted to term loans	1,272
Total	50,926
Commercial | Income producing commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	661,242
2019	520,201
2018	493,991
2017	287,602
2016	267,847
Prior	218,935
Revolvers	32,717
Revolvers converted to term loans	11,090
Total	2,493,625
Commercial | Income producing commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	630,081
2019	509,098
2018	480,546
2017	280,614
2016	229,065
Prior	205,567
Revolvers	32,717
Revolvers converted to term loans	9,243
Total	2,376,931
Commercial | Income producing commercial real estate | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	22,380
2019	2,986
2018	5,670
2017	1,459
2016	23,550
Prior	10,806
Revolvers	0
Revolvers converted to term loans	1,749
Total	68,600
Commercial | Income producing commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	8,781
2019	8,117
2018	7,775
2017	5,529
2016	15,232
Prior	2,562
Revolvers	0
Revolvers converted to term loans	98
Total	48,094
Commercial | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,666,856
2019	348,042
2018	292,819
2017	134,564
2016	105,773
Prior	57,328
Revolvers	492,709
Revolvers converted to term loans	6,777
Total	3,104,868
Commercial | Commercial & industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,658,045
2019	342,311
2018	285,481
2017	130,740
2016	103,886
Prior	55,855
Revolvers	466,479
Revolvers converted to term loans	5,834
Total	3,048,631
Commercial | Commercial & industrial | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,068
2019	1,949
2018	1,183
2017	522
2016	697
Prior	31
Revolvers	10,461
Revolvers converted to term loans	100
Total	16,011
Commercial | Commercial & industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	7,743
2019	3,782
2018	6,155
2017	3,302
2016	1,190
Prior	1,442
Revolvers	15,769
Revolvers converted to term loans	843
Total	40,226
Commercial | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2020	250,255
2019	237,246
2018	259,206
2017	115,988
2016	75,830
Prior	13,941
Revolvers	20,576
Revolvers converted to term loans	8,329
Total	981,371
Commercial | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	245,348
2019	236,060
2018	244,892
2017	103,853
2016	73,063
Prior	13,586
Revolvers	20,576
Revolvers converted to term loans	7,310
Total	944,688
Commercial | Construction | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,479
2019	585
2018	13,940
2017	11,789
2016	13
Prior	83
Revolvers	0
Revolvers converted to term loans	0
Total	27,889
Commercial | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,428
2019	601
2018	374
2017	346
2016	2,754
Prior	272
Revolvers	0
Revolvers converted to term loans	1,019
Total	8,794
Commercial | Equipment financing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	311,813
2019	299,314
2018	148,754
2017	48,677
2016	13,482
Prior	982
Revolvers	0
Revolvers converted to term loans	0
Total	823,022
Commercial | Equipment financing | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	311,697
2019	298,146
2018	146,957
2017	48,264
2016	13,336
Prior	950
Revolvers	0
Revolvers converted to term loans	0
Total	819,350
Commercial | Equipment financing | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	116
2019	1,168
2018	1,797
2017	413
2016	146
Prior	32
Revolvers	0
Revolvers converted to term loans	0
Total	3,672
Residential | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2020	157,893
2019	75,992
2018	5,222
2017	5,063
2016	3,992
Prior	15,034
Revolvers	0
Revolvers converted to term loans	70
Total	263,266
Residential | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	157,893
2019	75,907
2018	5,167
2017	5,026
2016	3,851
Prior	14,663
Revolvers	0
Revolvers converted to term loans	70
Total	262,577
Residential | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	85
2018	55
2017	37
2016	141
Prior	371
Revolvers	0
Revolvers converted to term loans	0
Total	689
Residential | Residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
2020	327,738
2019	231,733
2018	154,246
2017	142,010
2016	139,093
Prior	267,126
Revolvers	19
Revolvers converted to term loans	7,583
Total	1,269,548
Residential | Residential mortgage | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	325,928
2019	229,881
2018	150,863
2017	140,749
2016	138,321
Prior	258,641
Revolvers	19
Revolvers converted to term loans	7,264
Total	1,251,666
Residential | Residential mortgage | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,810
2019	1,852
2018	3,383
2017	1,261
2016	772
Prior	8,485
Revolvers	0
Revolvers converted to term loans	319
Total	17,882
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	684,611
Revolvers converted to term loans	22,266
Total	706,877
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	684,273
Revolvers converted to term loans	18,743
Total	703,016
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	338
Revolvers converted to term loans	3,523
Total	3,861
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	43,497
2019	31,495
2018	17,583
2017	6,184
2016	4,603
Prior	2,298
Revolvers	41,927
Revolvers converted to term loans	72
Total	147,659
Consumer | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	43,495
2019	31,411
2018	17,547
2017	6,074
2016	4,517
Prior	2,193
Revolvers	41,840
Revolvers converted to term loans	68
Total	147,145
Consumer | Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolvers	87
Revolvers converted to term loans	0
Total	87
Consumer | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2
2019	84
2018	36
2017	110
2016	86
Prior	105
Revolvers	0
Revolvers converted to term loans	4
Total	$ 427