Employee Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Contribution Plan Disclosure [Line Items]
Minimum age for participation (in years)	18 years
Minimum time at the company for participation (in days)	90 days
Total paid into 401(k)	$ 2,400	$ 2,300	$ 2,000
Non-US
Defined Contribution Plan Disclosure [Line Items]
Total paid into 401(k)	$ 2,300	$ 1,100	$ 893
Non-US | Minimum
Defined Contribution Plan Disclosure [Line Items]
Employer matching, percent of gross pay	2.00%
Non-US | Maximum
Defined Contribution Plan Disclosure [Line Items]
Employer matching, percent of gross pay	32.00%
Non-US | Management | Minimum
Defined Contribution Plan Disclosure [Line Items]
Employer matching, percent of gross pay	2.00%
Non-US | Management | Maximum
Defined Contribution Plan Disclosure [Line Items]
Employer matching, percent of gross pay	32.00%