Loans - Non-Accrual Loans Past Due (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Past due loans by class of loans [Abstract]
Total Past Due	$ 2,280	$ 535
Non-accrual Loans	5,837	6,922
Current Loans	1,961,543	1,042,241
Total Loans	1,969,660	1,049,698	$ 966,545
Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	839
Non-accrual Loans	0
Current Loans	3,651
Total Loans	4,490
Commercial real estate - owner occupied
Past due loans by class of loans [Abstract]
Total Past Due	892	0
Non-accrual Loans	0	0
Current Loans	442,236	250,440
Total Loans	443,128	250,440	238,224
Commercial real estate - owner occupied | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	653
Non-accrual Loans	0
Current Loans	442
Total Loans	1,095
Commercial real estate - nonowner occupied
Past due loans by class of loans [Abstract]
Total Past Due	0	0
Non-accrual Loans	0	0
Current Loans	435,181	184,688
Total Loans	435,181	184,688	174,342
Commercial real estate - nonowner occupied | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
Non-accrual Loans	0
Current Loans	920
Total Loans	920
Real estate construction
Past due loans by class of loans [Abstract]
Total Past Due	0	0
Non-accrual Loans	26	940
Current Loans	104,167	90,882
Total Loans	104,193	91,822	79,621
Real estate construction | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
Non-accrual Loans	0
Current Loans	0
Total Loans	0
Residential real estate
Past due loans by class of loans [Abstract]
Total Past Due	837	97
Non-accrual Loans	572	431
Current Loans	511,212	203,885
Total Loans	512,621	204,413	202,605
Residential real estate | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	186
Non-accrual Loans	0
Current Loans	2,189
Total Loans	2,375
Commercial
Past due loans by class of loans [Abstract]
Total Past Due	509	438
Non-accrual Loans	5,236	5,551
Current Loans	443,705	305,497
Total Loans	449,450	311,486	264,794
Commercial | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
Non-accrual Loans	0
Current Loans	94
Total Loans	94
Consumer
Past due loans by class of loans [Abstract]
Total Past Due	42	0
Non-accrual Loans	3	0
Current Loans	25,042	6,849
Total Loans	25,087	6,849	$ 6,959
Consumer | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
Non-accrual Loans	0
Current Loans	6
Total Loans	6
30-59 Days Past Due
Past due loans by class of loans [Abstract]
Total Past Due	2,007	438
30-59 Days Past Due | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	839
30-59 Days Past Due | Commercial real estate - owner occupied
Past due loans by class of loans [Abstract]
Total Past Due	892	0
30-59 Days Past Due | Commercial real estate - owner occupied | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	653
30-59 Days Past Due | Commercial real estate - nonowner occupied
Past due loans by class of loans [Abstract]
Total Past Due	0	0
30-59 Days Past Due | Commercial real estate - nonowner occupied | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
30-59 Days Past Due | Real estate construction
Past due loans by class of loans [Abstract]
Total Past Due	0	0
30-59 Days Past Due | Real estate construction | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
30-59 Days Past Due | Residential real estate
Past due loans by class of loans [Abstract]
Total Past Due	677	0
30-59 Days Past Due | Residential real estate | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	186
30-59 Days Past Due | Commercial
Past due loans by class of loans [Abstract]
Total Past Due	397	438
30-59 Days Past Due | Commercial | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
30-59 Days Past Due | Consumer
Past due loans by class of loans [Abstract]
Total Past Due	41	0
30-59 Days Past Due | Consumer | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
60-89 Days Past Due
Past due loans by class of loans [Abstract]
Total Past Due	200	97
60-89 Days Past Due | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
60-89 Days Past Due | Commercial real estate - owner occupied
Past due loans by class of loans [Abstract]
Total Past Due	0	0
60-89 Days Past Due | Commercial real estate - owner occupied | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
60-89 Days Past Due | Commercial real estate - nonowner occupied
Past due loans by class of loans [Abstract]
Total Past Due	0	0
60-89 Days Past Due | Commercial real estate - nonowner occupied | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
60-89 Days Past Due | Real estate construction
Past due loans by class of loans [Abstract]
Total Past Due	0	0
60-89 Days Past Due | Real estate construction | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
60-89 Days Past Due | Residential real estate
Past due loans by class of loans [Abstract]
Total Past Due	160	97
60-89 Days Past Due | Residential real estate | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
60-89 Days Past Due | Commercial
Past due loans by class of loans [Abstract]
Total Past Due	39	0
60-89 Days Past Due | Commercial | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
60-89 Days Past Due | Consumer
Past due loans by class of loans [Abstract]
Total Past Due	1	0
60-89 Days Past Due | Consumer | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
90 Days Or Greater
Past due loans by class of loans [Abstract]
Total Past Due	73	0
90 Days Or Greater | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
90 Days Or Greater | Commercial real estate - owner occupied
Past due loans by class of loans [Abstract]
Total Past Due	0	0
90 Days Or Greater | Commercial real estate - owner occupied | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
90 Days Or Greater | Commercial real estate - nonowner occupied
Past due loans by class of loans [Abstract]
Total Past Due	0	0
90 Days Or Greater | Commercial real estate - nonowner occupied | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
90 Days Or Greater | Real estate construction
Past due loans by class of loans [Abstract]
Total Past Due	0	0
90 Days Or Greater | Real estate construction | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
90 Days Or Greater | Residential real estate
Past due loans by class of loans [Abstract]
Total Past Due	0	0
90 Days Or Greater | Residential real estate | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
90 Days Or Greater | Commercial
Past due loans by class of loans [Abstract]
Total Past Due	73	0
90 Days Or Greater | Commercial | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	0
90 Days Or Greater | Consumer
Past due loans by class of loans [Abstract]
Total Past Due	0	$ 0
90 Days Or Greater | Consumer | Receivables Acquired with Deteriorated Credit Quality
Past due loans by class of loans [Abstract]
Total Past Due	$ 0