Preferred Stock - Tables (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Jun. 11, 2014	May 31, 2014
Temporary Equity [Line Items]
Common Stock Voting Rights	one
Convertible preferred stock, shares authorized				69,505,831
Convertible preferred stock, shares outstanding		0		49,646,975
Convertible preferred stock, aggregate liquidation preference				$ 162,828
Convertible preferred stock, carrying value				$ 162,253
Series A Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized			18,604,666
Convertible preferred stock, shares outstanding			13,289,037
Convertible preferred stock, per share liquidation preference			$ 0.70
Convertible preferred stock, aggregate liquidation preference			$ 9,302
Convertible preferred stock, carrying value			$ 9,222
Series B Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized			16,225,758
Convertible preferred stock, shares outstanding			11,589,825
Convertible preferred stock, per share liquidation preference			$ 0.95
Convertible preferred stock, aggregate liquidation preference			$ 10,977
Convertible preferred stock, carrying value			$ 10,929
Series C Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized			13,281,250
Convertible preferred stock, shares outstanding			9,486,602
Convertible preferred stock, per share liquidation preference			$ 1.79
Convertible preferred stock, aggregate liquidation preference			$ 17,000
Convertible preferred stock, carrying value			$ 16,860
Series D Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized			6,550,505
Convertible preferred stock, shares outstanding			4,678,927
Convertible preferred stock, per share liquidation preference			$ 4.27
Convertible preferred stock, aggregate liquidation preference			$ 20,000
Convertible preferred stock, carrying value			$ 19,945
Series E Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized			6,429,159
Convertible preferred stock, shares outstanding			4,592,244
Convertible preferred stock, per share liquidation preference			$ 9.96
Convertible preferred stock, aggregate liquidation preference			$ 45,716
Convertible preferred stock, carrying value			$ 45,596
Series F Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized			8,414,493
Convertible preferred stock, shares outstanding			6,010,340
Convertible preferred stock, per share liquidation preference			$ 9.96
Convertible preferred stock, aggregate liquidation preference			$ 59,833
Convertible preferred stock, carrying value			$ 59,701