Income Taxes (Details 5)	12 Months Ended
	Dec. 31, 2017
United States Federal | Minimum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2014
United States Federal | Maximum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2016
State of California | Minimum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2013
State of California | Maximum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2016
MASSACHUSETTS | Minimum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2014
MASSACHUSETTS | Maximum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2016
OREGON | Minimum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2014
OREGON | Maximum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2016
SWEDEN | Minimum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2012
SWEDEN | Maximum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2016
UNITED KINGDOM | Minimum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2013
UNITED KINGDOM | Maximum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2016
BELGIUM | Minimum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2011
BELGIUM | Maximum
Income Tax Examination [Line Items]
Tax years open to examination by major taxing jurisdictions	2016