Loans - Schedule of Aging of Company's Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Nonaccrual loans
Total past due	$ 5,771	$ 4,080
Current	2,929,127	2,695,429
Total loans, excluding fees and costs	2,934,898	2,699,509
Unearned net loan fees	(793)	(304)
Total loans	2,934,105	2,699,205
Recorded investment in loans 90 days or more past due and accruing	657	505
30 - 59 Days past due
Nonaccrual loans
Total past due	4,365	859
60 - 89 Days past due
Nonaccrual loans
Total past due	649	591
90+ Days past due
Nonaccrual loans
Total past due	757	2,630
Commercial
Nonaccrual loans
Total past due	4,382	3,013
Current	1,212,619	1,171,557
Total loans, excluding fees and costs	1,217,001	1,174,570
Commercial | 30 - 59 Days past due
Nonaccrual loans
Total past due	4,157	703
Commercial | 60 - 89 Days past due
Nonaccrual loans
Total past due	200	185
Commercial | 90+ Days past due
Nonaccrual loans
Total past due	25	2,125
Real estate - mortgage
Nonaccrual loans
Total past due	590	317
Current	1,171,006	1,016,755
Total loans, excluding fees and costs	1,171,596	1,017,072
Real estate - mortgage | 30 - 59 Days past due
Nonaccrual loans
Total past due	204
Real estate - mortgage | 60 - 89 Days past due
Nonaccrual loans
Total past due	386	317
Construction and land
Nonaccrual loans
Total past due	657	156
Current	175,081	201,855
Total loans, excluding fees and costs	175,738	202,011
Recorded investment in loans 90 days or more past due and accruing	657
Construction and land | 30 - 59 Days past due
Nonaccrual loans
Total past due		156
Construction and land | 90+ Days past due
Nonaccrual loans
Total past due	657
Consumer
Nonaccrual loans
Total past due	142	594
Current	266,805	252,646
Total loans, excluding fees and costs	266,947	253,240
Recorded investment in loans 90 days or more past due and accruing		505
Consumer | 30 - 59 Days past due
Nonaccrual loans
Total past due	4
Consumer | 60 - 89 Days past due
Nonaccrual loans
Total past due	63	89
Consumer | 90+ Days past due
Nonaccrual loans
Total past due	75	505
Other
Nonaccrual loans
Current	103,616	52,616
Total loans, excluding fees and costs	103,616	52,616
Manufacturing | Commercial
Nonaccrual loans
Total past due		24
Current	96,618	135,026
Total loans, excluding fees and costs	96,618	135,050
Manufacturing | Commercial | 30 - 59 Days past due
Nonaccrual loans
Total past due		24
Finance and insurance | Commercial
Nonaccrual loans
Total past due	481
Current	49,870	64,279
Total loans, excluding fees and costs	50,351	64,279
Finance and insurance | Commercial | 30 - 59 Days past due
Nonaccrual loans
Total past due	456
Finance and insurance | Commercial | 90+ Days past due
Nonaccrual loans
Total past due	25
Health care | Commercial
Nonaccrual loans
Total past due	500	323
Current	153,523	126,188
Total loans, excluding fees and costs	154,023	126,511
Health care | Commercial | 30 - 59 Days past due
Nonaccrual loans
Total past due	500	323
Real estate services | Commercial
Nonaccrual loans
Total past due		183
Current	126,044	118,680
Total loans, excluding fees and costs	126,044	118,863
Real estate services | Commercial | 30 - 59 Days past due
Nonaccrual loans
Total past due		183
Construction | Commercial
Nonaccrual loans
Total past due	260
Current	58,458	57,906
Total loans, excluding fees and costs	58,718	57,906
Construction | Commercial | 30 - 59 Days past due
Nonaccrual loans
Total past due	260
Public administration | Commercial
Nonaccrual loans
Current	255,997
Total loans, excluding fees and costs	255,997	221,112
Wholesale and retail trade | Commercial
Nonaccrual loans
Current		221,112
Total loans, excluding fees and costs		221,112
Commercial - Other | Commercial
Nonaccrual loans
Total past due	3,141	2,483
Current	472,109	448,366
Total loans, excluding fees and costs	475,250	450,849
Commercial - Other | Commercial | 30 - 59 Days past due
Nonaccrual loans
Total past due	2,941	173
Commercial - Other | Commercial | 60 - 89 Days past due
Nonaccrual loans
Total past due	200	185
Commercial - Other | Commercial | 90+ Days past due
Nonaccrual loans
Total past due		2,125
Residential and commercial owner-occupied | Real estate - mortgage
Nonaccrual loans
Total past due	365	317
Current	475,158	436,538
Total loans, excluding fees and costs	475,523	436,855
Residential and commercial owner-occupied | Real estate - mortgage | 30 - 59 Days past due
Nonaccrual loans
Total past due	204
Residential and commercial owner-occupied | Real estate - mortgage | 60 - 89 Days past due
Nonaccrual loans
Total past due	161	317
Residential and commercial investor | Real estate - mortgage
Nonaccrual loans
Total past due	225
Current	695,848	578,892
Total loans, excluding fees and costs	696,073	578,892
Residential and commercial investor | Real estate - mortgage | 60 - 89 Days past due
Nonaccrual loans
Total past due	$ 225
Real estate - mortgage - Other | Real estate - mortgage
Nonaccrual loans
Current		1,325
Total loans, excluding fees and costs		$ 1,325