Loans - Age Analysis (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 5,977,647
Total Past Due	43,585
Total	6,021,232	$ 5,137,823
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current		5,107,870
Total Past Due		24,322
Total		5,132,192
Commercial, secured by real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	4,206,040
Total Past Due	33,452
Total	4,239,492
Commercial, secured by real estate | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current		3,569,008
Total Past Due		14,480
Total		3,583,488
Non-owner occupied commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,384,233
Total Past Due	14,713
Total	2,398,946
Owner occupied commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	811,408
Total Past Due	15,684
Total	827,092
Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	812,597
Total Past Due	628
Total	813,225
Non-owner occupied residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	197,802
Total Past Due	2,427
Total	200,229
Commercial, industrial and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	716,337
Total Past Due	1,852
Total	718,189
Commercial, industrial and other | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current		429,502
Total Past Due		1,488
Total		430,990
Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	265,649
Total Past Due	1,234
Total	266,883
Construction | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current		333,418
Total Past Due		967
Total		334,385
Equipment finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	115,124
Total Past Due	1,566
Total	116,690
Equipment finance | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current		110,546
Total Past Due		530
Total		111,076
Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	374,370
Total Past Due	3,010
Total	377,380
Residential mortgage | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current		331,337
Total Past Due		3,464
Total		334,801
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	300,127
Total Past Due	2,471
Total	302,598
Consumer | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current		334,059
Total Past Due		3,393
Total		337,452
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,255
30-59 Days Past Due | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		6,808
30-59 Days Past Due | Commercial, secured by real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,705
30-59 Days Past Due | Commercial, secured by real estate | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		3,578
30-59 Days Past Due | Non-owner occupied commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,256
30-59 Days Past Due | Owner occupied commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,759
30-59 Days Past Due | Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	208
30-59 Days Past Due | Non-owner occupied residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	482
30-59 Days Past Due | Commercial, industrial and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	125
30-59 Days Past Due | Commercial, industrial and other | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		353
30-59 Days Past Due | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
30-59 Days Past Due | Construction | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		0
30-59 Days Past Due | Equipment finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,338
30-59 Days Past Due | Equipment finance | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		166
30-59 Days Past Due | Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,046
30-59 Days Past Due | Residential mortgage | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,138
30-59 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,041
30-59 Days Past Due | Consumer | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,573
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,277
60-89 Days Past Due | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,889
60-89 Days Past Due | Commercial, secured by real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	950
60-89 Days Past Due | Commercial, secured by real estate | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,200
60-89 Days Past Due | Non-owner occupied commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	306
60-89 Days Past Due | Owner occupied commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	350
60-89 Days Past Due | Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
60-89 Days Past Due | Non-owner occupied residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	294
60-89 Days Past Due | Commercial, industrial and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
60-89 Days Past Due | Commercial, industrial and other | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		71
60-89 Days Past Due | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
60-89 Days Past Due | Construction | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		0
60-89 Days Past Due | Equipment finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	98
60-89 Days Past Due | Equipment finance | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		80
60-89 Days Past Due | Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	156
60-89 Days Past Due | Residential mortgage | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		251
60-89 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	73
60-89 Days Past Due | Consumer | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		287
Greater Than 89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	34,053
Greater Than 89 Days | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		15,625
Greater Than 89 Days | Commercial, secured by real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	27,797
Greater Than 89 Days | Commercial, secured by real estate | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		9,702
Greater Than 89 Days | Non-owner occupied commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	13,151
Greater Than 89 Days | Owner occupied commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12,575
Greater Than 89 Days | Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	420
Greater Than 89 Days | Non-owner occupied residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,651
Greater Than 89 Days | Commercial, industrial and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,727
Greater Than 89 Days | Commercial, industrial and other | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		1,064
Greater Than 89 Days | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,234
Greater Than 89 Days | Construction | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		967
Greater Than 89 Days | Equipment finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	130
Greater Than 89 Days | Equipment finance | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		284
Greater Than 89 Days | Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,808
Greater Than 89 Days | Residential mortgage | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		2,075
Greater Than 89 Days | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,357
Greater Than 89 Days | Consumer | Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		$ 1,533