Retirement Agreements And Other Postretirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the year	$ 0	$ 0
Interest cost on the projected benefit obligation	8	9
Amortization of unrecognized losses	0	2
Net periodic benefits costs	8	$ 11
Employee benefits and other payments	$ 10,800		$ 9,500