Retirement Agreements And Other Postretirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee benefits and other payments	$ 12,100		$ 12,100		$ 10,900
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	0	$ 0	0	$ 0
Interest cost on the projected benefit obligation	9	8	17	16
Amortization of unrecognized losses	0	0	0	0
Net periodic benefits costs	$ 9	$ 8	$ 17	$ 16