Income Taxes - Schedule of Income Tax Provision (Benefit) Related to Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
At statutory rate	$ (20,884)	$ (9,260)	$ (3,788)
State taxes	1	1	1
Change in valuation allowance	25,483	10,263	3,998
Tax credits	(5,098)	(1,347)	(345)
Stock-based compensation	445	160	60
Other	$ 53	$ 183	$ 74