Income Taxes (Narrative) (Details) € in Thousands, $ in Thousands		1 Months Ended		3 Months Ended		12 Months Ended
	Dec. 28, 2012 EUR (€)	Dec. 31, 2013 EUR (€)	Jan. 31, 2012 EUR (€)	Jun. 28, 2014 EUR (€)	Sep. 29, 2012 EUR (€)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Income Taxes [Line Items]
Percentage of earnings from continuing operations before income taxes attributable to the United States						57.00%
TCJA revaluation of deferred tax assets and liabilities						$ 106,107
Belgium tax reform revaluation of deferred tax assets and liabilities						44,439
Valuation allowance against deferred tax asset						362,963	$ 289,078
Increase (decrease) in the valuation allowance						73,885	1,498
Net operating loss carryforwards and tax credit						530,978	456,130
Net operating loss carryforwards in various foreign jurisdictions						455,161
Repatriation transition tax expense						105,165
Accumulated earnings						860,000
TCJA net provisional tax expense						45,249
Related transactions for repatriation transition tax expense						46,191
Gross unrecognized tax benefits						65,631	46,434	$ 51,037
Unrecognized tax benefits that would impact effective tax rate						52,433
Interest and penalties						8,252	8,020
Accrued/(reversed) interest and penalties						165	$ 2,170	$ (5,635)
Expected decrease in unrecognized tax benefits within next twelve months						$ 13,248
Domestic tax authority
Income Taxes [Line Items]
Effective income tax rate						43.10%	38.50%	39.80%
Foreign tax authority
Income Taxes [Line Items]
Effective income tax rate						3.20%	10.80%	0.70%
Foreign tax authority | Belgium
Income Taxes [Line Items]
Interest income related to interest tax examination refund | €					€ 1,583
Foreign tax authority | Tax year 2008 | Belgium
Income Taxes [Line Items]
Foreign tax assessment | €			€ 23,789	€ 30,131
Foreign tax authority | Tax year 2005 | Belgium
Income Taxes [Line Items]
Foreign tax assessment | €	€ 46,135
Foreign tax authority | Tax year 2009 | Belgium
Income Taxes [Line Items]
Foreign tax assessment | €	€ 35,567
Foreign tax authority | Tax year 2006 | Belgium
Income Taxes [Line Items]
Foreign tax assessment | €		€ 38,817
Foreign tax authority | Tax year 2007 | Belgium
Income Taxes [Line Items]
Foreign tax assessment | €		39,635
Foreign tax authority | Tax year 2010 | Belgium
Income Taxes [Line Items]
Foreign tax assessment | €		€ 43,117
State
Income Taxes [Line Items]
Net operating loss carryforwards and tax credit						$ 74,985
Foreign subsidiary and state net operating losses and tax credits
Income Taxes [Line Items]
Increase (decrease) in the valuation allowance						36,792	$ (9,364)
State deferred tax assets
Income Taxes [Line Items]
Valuation allowance against deferred tax asset						33,503
Operating loss carryforward, foreign jurisdiction
Income Taxes [Line Items]
Valuation allowance against deferred tax asset						$ 329,301