Allowance for Loan Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Allowance for loan losses
Loans, excluding consumer finance	$ 735,784	$ 695,383
Pass
Allowance for loan losses
Loans, excluding consumer finance	702,198	652,903
Special Mention
Allowance for loan losses
Loans, excluding consumer finance	4,611	9,988
Substandard
Allowance for loan losses
Loans, excluding consumer finance	23,664	28,215
Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	5,311	4,277
CVBK | Pass
Allowance for loan losses
Loans, excluding consumer finance		54,060
CVBK | Special Mention
Allowance for loan losses
Loans, excluding consumer finance		2,590
CVBK | Substandard
Allowance for loan losses
Loans, excluding consumer finance		5,740
CVBK | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance		196
Real estate - residential mortgage
Allowance for loan losses
Loans, excluding consumer finance	184,863	188,264
Real estate - residential mortgage | Pass
Allowance for loan losses
Loans, excluding consumer finance	179,963	181,814
Real estate - residential mortgage | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	1,235	2,037
Real estate - residential mortgage | Substandard
Allowance for loan losses
Loans, excluding consumer finance	2,835	2,761
Real estate - residential mortgage | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	830	1,652
Real estate - construction | Construction Lending
Allowance for loan losses
Loans, excluding consumer finance	41,449	47,062
Real estate - construction | Construction Lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	41,449	47,062
Real estate - construction | Consumer lot lending
Allowance for loan losses
Loans, excluding consumer finance	3,333	8,670
Real estate - construction | Consumer lot lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	3,333	8,670
Commercial, financial and agricultural | Commercial real estate lending
Allowance for loan losses
Loans, excluding consumer finance	304,490	261,786
Commercial, financial and agricultural | Commercial real estate lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	293,292	243,427
Commercial, financial and agricultural | Commercial real estate lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	2,874	5,860
Commercial, financial and agricultural | Commercial real estate lending | Substandard
Allowance for loan losses
Loans, excluding consumer finance	4,528	10,880
Commercial, financial and agricultural | Commercial real estate lending | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	3,796	1,619
Commercial, financial and agricultural | Land acquisition and development lending
Allowance for loan losses
Loans, excluding consumer finance	39,844	43,472
Commercial, financial and agricultural | Land acquisition and development lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	24,253	29,595
Commercial, financial and agricultural | Land acquisition and development lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance		565
Commercial, financial and agricultural | Land acquisition and development lending | Substandard
Allowance for loan losses
Loans, excluding consumer finance	15,591	13,312
Commercial, financial and agricultural | Builder line lending
Allowance for loan losses
Loans, excluding consumer finance	29,596	22,391
Commercial, financial and agricultural | Builder line lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	29,596	21,235
Commercial, financial and agricultural | Builder line lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance		789
Commercial, financial and agricultural | Builder line lending | Substandard
Allowance for loan losses
Loans, excluding consumer finance		367
Commercial, financial and agricultural | Commercial business lending
Allowance for loan losses
Loans, excluding consumer finance	63,954	62,739
Commercial, financial and agricultural | Commercial business lending | Pass
Allowance for loan losses
Loans, excluding consumer finance	63,749	62,044
Commercial, financial and agricultural | Commercial business lending | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	34	255
Commercial, financial and agricultural | Commercial business lending | Substandard
Allowance for loan losses
Loans, excluding consumer finance	137	309
Commercial, financial and agricultural | Commercial business lending | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	34	131
Equity lines
Allowance for loan losses
Loans, excluding consumer finance	55,237	52,600
Equity lines | Pass
Allowance for loan losses
Loans, excluding consumer finance	53,870	51,186
Equity lines | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	465	480
Equity lines | Substandard
Allowance for loan losses
Loans, excluding consumer finance	251	177
Equity lines | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance	651	757
Consumer Loan
Allowance for loan losses
Loans, excluding consumer finance	13,018	8,399
Consumer Loan | Pass
Allowance for loan losses
Loans, excluding consumer finance	12,693	7,870
Consumer Loan | Special Mention
Allowance for loan losses
Loans, excluding consumer finance	3	2
Consumer Loan | Substandard
Allowance for loan losses
Loans, excluding consumer finance	$ 322	409
Consumer Loan | Substandard Nonaccrual
Allowance for loan losses
Loans, excluding consumer finance		$ 118