Income Taxes - Summary of Open Tax Positions (Details)	12 Months Ended
	Dec. 31, 2014
Minimum [Member] | United States Federal [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2011
Minimum [Member] | United States State [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2008
Minimum [Member] | Germany [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2010	[1]
Minimum [Member] | Hong Kong [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2008
Minimum [Member] | Italy [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2008	[1]
Minimum [Member] | Sweden [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2008
Minimum [Member] | United Kingdom [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2012
Maximum [Member] | United States Federal [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2014
Maximum [Member] | United States State [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2014
Maximum [Member] | Germany [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2014	[1]
Maximum [Member] | Hong Kong [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2014
Maximum [Member] | Italy [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2014	[1]
Maximum [Member] | Sweden [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2014
Maximum [Member] | United Kingdom [Member]
Income Tax Contingency [Line Items]
Open Tax Years by Major Tax Jurisdiction	2014

[1] Includes federal as well as local jurisdictions.