Net Loss Per Share Attributable to Common Shareholders and Stockholders (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Weighted-Average Equity Instruments Excluded from Calculation of Diluted Net Loss Per Share

The following weighted-average equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented:

	Year Ended December 31,
	2016		2015		2014
Series A convertible preferred shares/stock		611,392		2,172,520		1,557,870
Series B convertible preferred stock		1,407,097		4,047,734		—
Unvested restricted common stock		100,634		153,355		—
Options to purchase common stock		1,063,778		450,458		—
Forward sale contract for Series A convertible preferred shares		—		—		447,482
Unvested Class B common shares		—		—		151,936