Income Taxes - Change In Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance [Line Items]
Net increase in Valuation allowance	$ 27,273
Net increase (decrease) in valuation allowance	27,273	$ 20,794	$ 12,437
U.S.
Valuation Allowance [Line Items]
Net increase in Valuation allowance	23,147
Net increase (decrease) in valuation allowance	23,147	22,582	13,256
Foreign
Valuation Allowance [Line Items]
Net increase in Valuation allowance	4,126
Net increase (decrease) in valuation allowance	$ 4,126	$ (1,788)	$ (819)