Employee Benefit Plans (Pension And Other Postretirement Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2,270	$ 2,991	$ 4,541	$ 5,982
Expected return on plan assets	(3,080)	(4,499)	(6,161)	(8,996)
Pension Settlement	(1,371)	(487)	(1,371)	(487)
Net benefit credit	(2,181)	(1,995)	(2,991)	(3,501)
Other postretirement benefits plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	139	171	279	341
Interest cost	919	1,059	1,837	2,117
Net benefit credit	$ 1,058	$ 1,230	$ 2,116	$ 2,458