Retirement Agreements and Other Postretirement Benefit Plan Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Service cost – benefits earned during the year	$ 0	$ 0	$ 0
Interest cost on the projected benefit obligation	33	32	37
Amortization of unrecognized prior service cost	0	0	0
Amortization of unrecognized loss	0	0	9
Net periodic benefits cost at end of year	$ 33	$ 32	$ 46