Employee Benefit Plan (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 1988	Dec. 31, 1987	Dec. 31, 1985
Defined Benefit Plan Disclosure [Line Items]
Amount borrowed						$ 2,000,000
Employee stock ownership plan debt structure interest rate description		prime rate
Employee stock ownership plan, term of loan		40 years
Employee stock ownership plan, amount of additional loan				$ 1,942,000	$ 1,942,000
Outstanding shares subject to repurchase obligation		0
ESOP, number of allocated shares since inception		414,515
ESOP, number of unallocated shares	104,320	87,425	104,320
ESOP, compensation expenses	$ 101,000	$ 101,000	$ 101,000
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Future obligation of benefits	644,000	583,000	644,000
Additional expense		100,000
Estimated future annual expenses associated with the plan are immaterial. Included in accumulated other comprehensive income (loss)	$ 67,000	$ 63,000	$ 67,000