Summary of Significant Accounting Policies - Nature of Operations and Significant Group Concentration of Credit Risk (Details)	12 Months Ended
	Dec. 31, 2018 subsidiary
Individual State Concentration Risk | Investment concentration risk | Obligations of states and political subdivisions
Concentration risk
Concentration Risk, Percentage	13.70%
Individual State Concentration Risk | Investment concentration risk | Obligations of states and political subdivisions | Minimum
Concentration risk
Concentration risk, threshold percentage	10.00%
Individual Issuer Concentration Risk | Loan Portfolio Concentration Risk | Obligations of states and political subdivisions
Concentration risk
Concentration Risk, Percentage	3.60%
Category of loan concentration risk | Loan Portfolio Concentration Risk | Commercial, financial and agricultural
Concentration risk
Concentration Risk, Percentage	42.90%
Category of loan concentration risk | Loan Portfolio Concentration Risk | Non-prime consumer finance loans
Concentration risk
Concentration Risk, Percentage	26.80%
C&F Bank
Concentration risk
Number of wholly owned subsidiaries	5