Fair Value of Assets and Liabilities - Financial Assets Measured at Fair Value on Non-Recurring Basis (Details) $ in Thousands	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Fair value assets and liabilities - Nonrecurring Basis
Impaired loans measured for impairment using the fair value of the collateral	$ 0
Nonrecurring
Fair value assets and liabilities - Nonrecurring Basis
Financial assets measured at fair value on a non-recurring basis	268	$ 370
Nonrecurring | Impaired loans, net
Fair value assets and liabilities - Nonrecurring Basis
Financial assets measured at fair value on a non-recurring basis		102
Nonrecurring | Other real estate owned, net
Fair value assets and liabilities - Nonrecurring Basis
Financial assets measured at fair value on a non-recurring basis	268	268
Level 3 | Nonrecurring
Fair value assets and liabilities - Nonrecurring Basis
Financial assets measured at fair value on a non-recurring basis	$ 268	370
Other real estate owned, net, valuation technique	cffi:ValuationTechniqueAppraisalsMember
Other real estate owned, net, measurement input	us-gaap:MeasurementInputDiscountRateMember
Level 3 | Nonrecurring | Minimum
Fair value assets and liabilities - Nonrecurring Basis
Other real estate owned, input	0.33
Level 3 | Nonrecurring | Impaired loans, net
Fair value assets and liabilities - Nonrecurring Basis
Financial assets measured at fair value on a non-recurring basis		102
Level 3 | Nonrecurring | Other real estate owned, net
Fair value assets and liabilities - Nonrecurring Basis
Financial assets measured at fair value on a non-recurring basis	$ 268	$ 268