Employee Benefit Plans - Other Retirement Agreements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jul. 01, 2019
Other Retirement Agreements
Employee Benefit Plans
Threshold period of service of employee to be eligible for plan	10 years
Threshold age of employees eligible for plan	75 years
Payments to be made to each director	$ 120,000
Payments deferred (in years)	10 years
Age at which the retirement benefits would begin	65 years
Period in which the accrued balance at the termination date will be paid	1 year
Total accrued balance of benefit			$ 1,500,000
Expense incurred under the plan	$ 34,000	$ 61,000
Accrued liability	301,000	1,774,000
Other Retirement Agreements | Minimum
Employee Benefit Plans
Employee annual benefits for life	66,000
Other Retirement Agreements | Maximum
Employee Benefit Plans
Employee annual benefits for life	85,000
Life insurance policies
Employee Benefit Plans
Employee annual benefits for life	$ 7,174,000	$ 7,157,000