Stock-Based Compensation - Summary of Unvested Shares of Common Stock Activity (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2016 $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares Outstanding, Balance | shares	136
Number of Shares, Issued | shares	59
Number of Shares, Vested | shares	(77)
Number of Shares Outstanding, Balance | shares	118
Weighted-Average Exercise Price Per Share, Balance | $ / shares	$ 1.76
Weighted-Average Exercise Price Per Share, Issued | $ / shares	5.35
Weighted-Average Exercise Price Per Share, Vested | $ / shares	2.15
Weighted-Average Exercise Price Per Share, Balance | $ / shares	$ 3.30