Commitments and Contingencies - Narrative (Details)	1 Months Ended	3 Months Ended
	Mar. 31, 2008 shares	Mar. 31, 2019 USD ($) action $ / shares	Dec. 31, 2018 USD ($) $ / shares
Loss Contingencies [Line Items]
Amount of loans sold to FHLB		$ 68,200,000
Federal Home Loan Bank, First Loss Account Established		776,000
Bank recourse obligation		$ 524,000
Bank recourse obligation, percentage of loans outstanding		0.77%
Reserve as a percentage of outstanding CE		10.00%
Reserve for loans sold		$ 227,000
Outstanding Delinquencies On Loans Sold to Federal Home Loan Bank		$ 0	$ 0
Severance agreement, period of base compensation disbursed as lump sum payment (in months)		24 months
Change of control agreement, notice required to cancel agreement (in months)		24 months
Change of control agreement, executive payment, period following change in control (in months)		12 months
Number of shares received in an IPO | shares	7,158
Common stock, conversion ratio	1.6298
Carrying value of stock		$ 0
Pending material legal actions | action		0
Visa, Inc.
Loss Contingencies [Line Items]
Market value of stock (in dollars per share) | $ / shares		$ 156.19	$ 131.94
Maximum
Loss Contingencies [Line Items]
Change of control agreement, executive payment, period prior to change in control (in months)		6 months
Change of control agreement, period of base compensation disbursed as lump sum payment (in months)		12 months
Commitments to Extend Credit
Loss Contingencies [Line Items]
Reserve for estimated losses		$ 285,000	$ 299,000
Guarantee on loans sold
Loss Contingencies [Line Items]
Reserve for estimated losses		$ 1,000,000	$ 1,000,000