Employee Benefit Plans (Pension And Other Postretirement Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2,376	$ 2,736	$ 6,917	$ 8,718
Expected return on plan assets	(2,906)	(3,913)	(9,067)	(12,909)
Pension settlement	(613)	(229)	(1,984)	(716)
Net benefit credit	(1,143)	(1,406)	(4,134)	(4,907)
Other postretirement benefits plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	140	170	419	511
Interest cost	918	1,058	2,755	3,175
Curtailments	0	(520)	0	(520)
Net benefit credit	$ 1,058	$ 708	$ 3,174	$ 3,166