Income Taxes (Schedule of Provision for Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ 85,800	$ (4,500)	$ 47,300
Foreign	3,000	9,400	3,900
State and local	6,700	3,300	6,600
Total current income tax expense	95,500	8,200	57,800
Deferred:
Federal	6,100	25,700	14,900
Foreign	(6,800)	(19,900)	2,700
State and local	(3,000)	(2,000)	1,000
Total deferred income tax expense	(3,935)	3,925	13,756
Provision for income taxes	91,784	11,957	76,429
Continuing Operations [Member]
Deferred:
Total deferred income tax expense	$ (3,700)	$ 3,800	$ 18,600