Loans - Risk category of loans by loan segment (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	$ 2,002,817	$ 1,912,038
Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	1,953,248	1,904,068
Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	45,804	5,275
Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	3,765	2,695
Commercial
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	299,425	276,035
Commercial | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	277,533	275,741
Commercial | Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	21,625	21
Commercial | Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	267	273
Construction and Land Development
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	183,350	196,776
Construction and Land Development | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	183,045	196,462
Construction and Land Development | Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	135	138
Construction and Land Development | Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	170	176
HELOC and 1-4 Family Junior Mortgage
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	30,928	28,621
HELOC and 1-4 Family Junior Mortgage | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	30,790	28,483
HELOC and 1-4 Family Junior Mortgage | Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	138	138
1st REM - 1-4 Family
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	34,552	36,671
1st REM - 1-4 Family | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	34,253	36,370
1st REM - 1-4 Family | Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	123	124
1st REM - 1-4 Family | Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	176	177
LOCs and 2nd REM - Rentals
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	19,935	18,671
LOCs and 2nd REM - Rentals | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	19,156	17,890
LOCs and 2nd REM - Rentals | Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	476	479
LOCs and 2nd REM - Rentals | Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	303	302
1st REM - Rentals
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	187,175	176,648
1st REM - Rentals | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	185,643	174,781
1st REM - Rentals | Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	768	1,287
1st REM - Rentals | Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	764	580
Multifamily
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	536,380	515,014
Multifamily | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	536,380	515,014
CRE Owner Occupied
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	75,207	66,584
CRE Owner Occupied | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	72,540	65,411
CRE Owner Occupied | Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	820
CRE Owner Occupied | Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	1,847	1,173
CRE Non-owner Occupied
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	631,541	592,545
CRE Non-owner Occupied | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	609,598	589,457
CRE Non-owner Occupied | Watch
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	21,719	3,088
CRE Non-owner Occupied | Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	224
Consumer and other
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	4,324	4,473
Consumer and other | Pass
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	4,310	4,459
Consumer and other | Substandard
Risk category of loans by loan segment, based on the most recent analysis performed by management
Totals	$ 14	$ 14