Loans - Internal Risk Rating Grades (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
INTERNAL RISK RATING
Loan Receivables	$ 917,667	$ 902,345
Pass
INTERNAL RISK RATING
Loan Receivables	902,194	890,498
Special Mention
INTERNAL RISK RATING
Loan Receivables	6,646	2,260
Substandard
INTERNAL RISK RATING
Loan Receivables	8,827	9,587
Construction, Land and Land Development
INTERNAL RISK RATING
Loan Receivables	110,598	109,475
Construction, Land and Land Development | Pass
INTERNAL RISK RATING
Loan Receivables	108,524	107,306
Construction, Land and Land Development | Special Mention
INTERNAL RISK RATING
Loan Receivables		68
Construction, Land and Land Development | Substandard
INTERNAL RISK RATING
Loan Receivables	2,074	2,101
Commercial Mortgages (Non-Owner Occupied)
INTERNAL RISK RATING
Loan Receivables	178,532	180,074
Commercial Mortgages (Non-Owner Occupied) | Pass
INTERNAL RISK RATING
Loan Receivables	177,969	178,936
Commercial Mortgages (Non-Owner Occupied) | Substandard
INTERNAL RISK RATING
Loan Receivables	563	1,138
Commercial Mortgages (Owner Occupied)
INTERNAL RISK RATING
Loan Receivables	82,990	87,241
Commercial Mortgages (Owner Occupied) | Pass
INTERNAL RISK RATING
Loan Receivables	82,423	85,897
Commercial Mortgages (Owner Occupied) | Special Mention
INTERNAL RISK RATING
Loan Receivables	154	107
Commercial Mortgages (Owner Occupied) | Substandard
INTERNAL RISK RATING
Loan Receivables	413	1,237
Residential First Mortgages
INTERNAL RISK RATING
Loan Receivables	305,252	298,894
Residential First Mortgages | Pass
INTERNAL RISK RATING
Loan Receivables	301,753	295,372
Residential First Mortgages | Special Mention
INTERNAL RISK RATING
Loan Receivables	478	1,071
Residential First Mortgages | Substandard
INTERNAL RISK RATING
Loan Receivables	3,021	2,451
Residential Revolving and Junior Mortgages
INTERNAL RISK RATING
Loan Receivables	35,875	38,313
Residential Revolving and Junior Mortgages | Pass
INTERNAL RISK RATING
Loan Receivables	34,552	37,206
Residential Revolving and Junior Mortgages | Special Mention
INTERNAL RISK RATING
Loan Receivables	63
Residential Revolving and Junior Mortgages | Substandard
INTERNAL RISK RATING
Loan Receivables	1,260	1,107
Commercial and Industrial
INTERNAL RISK RATING
Loan Receivables	187,531	164,608
Commercial and Industrial | Pass
INTERNAL RISK RATING
Loan Receivables	180,375	162,392
Commercial and Industrial | Special Mention
INTERNAL RISK RATING
Loan Receivables	5,951	893
Commercial and Industrial | Substandard
INTERNAL RISK RATING
Loan Receivables	1,205	1,323
Consumer
INTERNAL RISK RATING
Loan Receivables	16,889	23,740
Consumer | Pass
INTERNAL RISK RATING
Loan Receivables	16,598	23,389
Consumer | Special Mention
INTERNAL RISK RATING
Loan Receivables		121
Consumer | Substandard
INTERNAL RISK RATING
Loan Receivables	$ 291	$ 230