Income Taxes (Components Of Income Tax Provision) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Abstract]
Current: U.S. federal													$ (83)	$ (2,110)	$ 10,753
Current: State													741	30	169
Current: Foreign													12,711	8,099	925
Current: Total													13,369	6,019	11,847
Deferred: U.S. federal														(1,245)	(5,252)
Deferred: State													1,097		(225)
Deferred: Foreign													(6,664)	(5,321)	2,602
Deferred: Total													(5,567)	(6,566)	(2,875)
Total income tax (benefit) provision	$ 971	$ 3,723	$ 2,067	$ 1,041	$ (1,212)	$ (2,214)	$ 1,700	$ 1,179	$ 29,535	$ (3,524)	$ (10,096)	$ (6,943)	$ 7,802	$ (547)	$ 8,972