Income Taxes (Provision for Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
U.S. Federal:
Current									$ (18,789)	$ (56,743)	$ 25,774
Deferred									11,577	61,514	(23,863)
U.S. Federal: Total									(7,212)	4,771	1,911
U.S. State and Local:
Current									(9,142)	(12,214)	(3,022)
Deferred									8,043	866	13,426
U.S. State and Local: Total									(1,099)	(11,348)	10,404
International:
Current									9,993	11,308	(7,679)
Deferred									(14,689)	1,685	9,023
International: Total									(4,696)	12,993	1,344
Total current									(17,938)	(57,649)	15,073
Total deferred									4,931	64,065	(1,414)
(Benefit) provision for income taxes	$ 344	$ (24,895)	$ 3,724	$ 7,820	$ (10,819)	$ (2,468)	$ 2,205	$ 17,498	$ (13,007)	$ 6,416	$ 13,659
Effective tax rate									(47.90%)	3.40%	7.10%