Purchased Intangible Assets and Goodwill (Changes in Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Goodwill	$ 178,987	$ 178,987
Accumulated impairment losses	(14,875)	(14,875)
Goodwill, net beginning balance	164,112	164,112
Other	0	0
Goodwill, ending balance	178,987	178,987
Accumulated impairment losses	(14,875)	(14,875)
Goodwill, net ending balance	164,112	164,112
United States & Canada
Goodwill [Roll Forward]
Goodwill	43,872	43,872
Accumulated impairment losses	(5,441)	(5,441)
Goodwill, net beginning balance	38,431	38,431
Other	0	0
Goodwill, ending balance	43,872	43,872
Accumulated impairment losses	(5,441)	(5,441)
Goodwill, net ending balance	38,431	38,431
Latin America
Goodwill [Roll Forward]
Goodwill	125,681	125,681
Accumulated impairment losses	0	0
Goodwill, net beginning balance	125,681	125,681
Other	0	0
Goodwill, ending balance	125,681	125,681
Accumulated impairment losses	0	0
Goodwill, net ending balance	125,681	125,681
EMEA
Goodwill [Roll Forward]
Goodwill	9,434	9,434
Accumulated impairment losses	(9,434)	(9,434)
Goodwill, net beginning balance	0	0
Other	0	0
Goodwill, ending balance	9,434	9,434
Accumulated impairment losses	(9,434)	(9,434)
Goodwill, net ending balance	$ 0	$ 0