Operating Segments and Geographic Information (Information Related To Reportable Operating Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	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, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 187,417	$ 245,888	$ 323,828	$ 279,140	$ 208,678	$ 274,088	$ 345,671	$ 262,193	$ 1,036,273	$ 1,090,630	$ 1,198,223
Total consolidated operating income (loss)	$ (39,787)	$ (1,215)	$ 20,605	$ 14,243	$ (65,581)	$ (20,730)	$ 16,349	$ (2,362)	(6,154)	(72,324)	(4,726)
Foreign currency loss, net									(2,454)	(3,332)	(4,885)
Interest income									692	967	1,664
Interest expense									(836)	(969)	(806)
Other income (expense), net									1,539	914	204
Loss before income taxes									(7,213)	(74,744)	(8,549)
Depreciation and amortization									34,043	35,993	37,413
Total cash paid for Property Plant and Equipment									13,233	12,826	15,991
Total cash paid for Intangible Assets									8,961	5,660	41,035
Other businesses [Member]
Segment Reporting Information [Line Items]
Revenues									745	1,096	794
Total consolidated operating income (loss)									(26,935)	(30,092)	(19,400)
Depreciation and amortization									6,830	7,634	5,900
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues									1,035,528	1,089,534	1,197,429
Total consolidated operating income (loss)									155,508	113,498	147,999
Depreciation and amortization									12,184	13,543	22,155
Total cash paid for Property Plant and Equipment									13,233	12,826	15,991
Total cash paid for Intangible Assets									8,961	5,660	41,035
Operating Segments [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Revenues									467,006	476,210	489,915
Total consolidated operating income (loss)									58,844	49,422	48,347
Depreciation and amortization									5,787	7,401	11,670
Total cash paid for Property Plant and Equipment									6,851	6,611	6,807
Total cash paid for Intangible Assets									8,961	5,459	40,532
Operating Segments [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenues									395,078	424,491	473,910
Total consolidated operating income (loss)									78,907	48,447	75,135
Depreciation and amortization									4,264	3,913	6,724
Total cash paid for Property Plant and Equipment									4,994	4,705	6,123
Total cash paid for Intangible Assets									0	0	295
Operating Segments [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Revenues									173,444	188,833	233,604
Total consolidated operating income (loss)									17,757	15,629	24,517
Depreciation and amortization									2,133	2,229	3,761
Total cash paid for Property Plant and Equipment									1,388	1,510	3,061
Total cash paid for Intangible Assets									0	201	208
Intersegment eliminations [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income (loss)									0	0	(1,498)
Unallocated corporate and other [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income (loss)									(134,727)	(155,730)	(131,827)
Depreciation and amortization									$ 15,029	$ 14,816	$ 9,358