Employee Benefit Plans - Defined Benefit Plans - Plan Requirements (Details) (The Bank, Cash Balance Plan)	12 Months Ended
Dec. 31, 2014
The Bank \| Cash Balance Plan
Defined Benefit Plans
Minimum age	21 years
Basis points added to 30-year Treasuries yield to compute interest credit (as a percent)	1.50%

Percentage points added to the reference rate to compute the interest credited to each participant account in the defined benefit plan.

No definition available.

Name:	cffi_DefinedBenefitPlanInterestCreditBasisSpreadOnVariableRate
Namespace Prefix:	cffi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration