Retirement Agreements and Other Postretirement Benefit Plan Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Service cost – benefits earned during the year	$ 0	$ 0
Interest cost on the projected benefit obligation	31	33
Amortization of unrecognized prior service cost	0	0
Amortization of unrecognized loss	0	0
Net periodic benefits cost at end of year	$ 31	$ 33