Retirement Agreements And Other Postretirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Retirement Benefits [Abstract]
Liability for employee benefits and other payments	$ 12,400		$ 12,400		$ 12,200
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	0	$ 0	0	$ 0
Interest cost on the projected benefit obligation	8	9	16	17
Amortization of unrecognized losses	0	0	0	0
Net periodic benefits costs	$ 8	$ 9	$ 16	$ 17