Equity (Schedule of Changes in Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Loss [Line Items]
Accumulated other comprehensive loss, beginning balance	$ (65,814)	$ (72,351)	$ (34,004)
Unrealized gains (losses), net of tax	2,102	6,537	(38,347)
Accumulated other comprehensive loss, ending balance	(63,712)	(65,814)	(72,351)
Foreign Currency [Member]
Accumulated Other Comprehensive Loss [Line Items]
Accumulated other comprehensive loss, beginning balance	(64,478)	(67,063)	(28,716)
Unrealized gains (losses), net of tax	1,627	2,585	(38,347)
Accumulated other comprehensive loss, ending balance	(62,851)	(64,478)	(67,063)
Other [Member]
Accumulated Other Comprehensive Loss [Line Items]
Accumulated other comprehensive loss, beginning balance	(1,336)	(5,288)	(5,288)
Unrealized gains (losses), net of tax	475	3,952	0
Accumulated other comprehensive loss, ending balance	$ (861)	$ (1,336)	$ (5,288)