Stockholders' Equity - Additional Information (Details)				1 Months Ended	12 Months Ended
	Jul. 25, 2016 shares	Jul. 19, 2016 shares	Jul. 18, 2016 shares	Oct. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) Member $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares
Stockholders Equity [Line Items]
Preferred stock, shares issued					0	0
Preferred stock, shares outstanding					0	0
Minimum percentage of outstanding shares of convertible preferred stockholders held by owners voting other than Deemed Liquidation Events						66.67%
Number of members of Board of Directors elected by holders of convertible preferred stock | Member						4
Number of members of Board of Directors elected by holders of common stock | Member						1
Number of members of Board of Directors elected by holders of common stock and any other series or class of voting stock | Member						1
Convertible preferred stock, conversion ratio						100.00%
Minimum qualified initial public offering stock price per share | $ / shares						$ 24.0410
Minimum gross proceeds from issuance of qualified initial public offering | $						$ 50,000,000
Preferred stock, cash dividend rate						8.00%
Preferred stock, dividends declared | $ / shares						$ 0
Shares reserved for issuance						1,345,430
Shares available for future grant					1,891,092	751,661	977,297
Options exercised					129,809	51,994
Intrinsic value of options exercised | $					$ 1,100,000	$ 100,000
Options exercised, cash received | $					$ 200,000	$ 100,000
Employee Stock Option
Stockholders Equity [Line Items]
Weighted average grant date fair value of options granted | $ / shares					$ 7.33	$ 3.01	$ 0.67
Unrecognized compensation expense related to unvested options, net of estimated forfeitures | $					$ 5,700,000
Estimated weighted average period					2 years 8 months 1 day
Non Employee Stock Option
Stockholders Equity [Line Items]
Weighted average grant date fair value of options granted | $ / shares					$ 5.67	$ 1.61	$ 0
Unrecognized compensation expense related to unvested options, net of estimated forfeitures | $					$ 200,000
Estimated weighted average period					1 year 9 months 11 days
2012 Equity Incentive Plan
Stockholders Equity [Line Items]
Shares reserved for issuance					3,107,517
2012 Equity Incentive Plan | Minimum
Stockholders Equity [Line Items]
Percentage of voting rights owned by employees					10.00%
Percentage of exercise prices for incentive and non-statutory stock options expressed as fair market value of stock					110.00%
2012 Equity Incentive Plan | Maximum
Stockholders Equity [Line Items]
Options granted expiry term					10 years
2016 Equity Incentive Plan
Stockholders Equity [Line Items]
Shares reserved for issuance			1,500,000
Number of shares rolled out from old plan to new plan			705,862
Shares available for future grant					1,891,092
Number of shares will increase automatically through every year on specified date					--01-01
Number of shares automatically increase continuing through maximum period					tenth calendar year
Proportion of outstanding shares of common stock			5.00%
Incentive stock option granted to stockholders percentage			10.00%
2016 Equity Incentive Plan | Minimum
Stockholders Equity [Line Items]
Options vested expiry term			4 years
2016 Equity Incentive Plan | Maximum
Stockholders Equity [Line Items]
Options granted expiry term			10 years
2016 Equity Incentive Plan | Maximum | 10% Stockholders
Stockholders Equity [Line Items]
Options granted expiry term			5 years
2016 Employee Stock Purchase Plan
Stockholders Equity [Line Items]
Shares reserved for issuance		210,000
Number of shares will increase automatically through every year on specified date					--01-01
Number of shares automatically increase continuing through maximum period					first ten calendar years
Proportion of outstanding shares of common stock		1.00%
Common Stock
Stockholders Equity [Line Items]
Number of common stock issued upon conversion of convertible preferred stock	13,820,301
Options exercised					129,806	51,994
Convertible Preferred Stock
Stockholders Equity [Line Items]
Preferred stock, shares issued						13,820,301
Preferred stock, shares outstanding						13,820,301
Convertible Preferred Stock, Series C
Stockholders Equity [Line Items]
Preferred stock, shares issued				4,325,954	0	4,325,954
Preferred stock, shares outstanding					0	4,325,954
Original issue price per share | $ / shares				$ 15.0256		$ 15.0256
Proceeds from issuance of convertible preferred stock, net of placement agent fee and expenses | $				$ 62,800,000	$ 0	$ 62,780,000	$ 0
Liquidation preference price per share | $ / shares						$ 15.0256
Preferred stock conversion price per share | $ / shares						$ 15.0256
Convertible Preferred Stock, Series Seed
Stockholders Equity [Line Items]
Preferred stock, shares issued					0	627,867
Preferred stock, shares outstanding					0	627,867
Original issue price per share | $ / shares						$ 2.2300
Liquidation preference price per share | $ / shares						2.2300
Preferred stock conversion price per share | $ / shares						$ 2.2300
Convertible Preferred Stock, Series A
Stockholders Equity [Line Items]
Preferred stock, shares issued					0	5,022,876
Preferred stock, shares outstanding					0	5,022,876
Original issue price per share | $ / shares						$ 5.9727
Proceeds from issuance of convertible preferred stock, net of placement agent fee and expenses | $					$ 0	$ 0	14,998,000
Liquidation preference price per share | $ / shares						$ 5.9727
Preferred stock conversion price per share | $ / shares						$ 5.9727
Convertible Preferred Stock, Series B
Stockholders Equity [Line Items]
Preferred stock, shares issued					0	3,843,604
Preferred stock, shares outstanding					0	3,843,604
Original issue price per share | $ / shares						$ 11.1942
Proceeds from issuance of convertible preferred stock, net of placement agent fee and expenses | $					$ 0	$ 0	$ 42,388,000
Liquidation preference price per share | $ / shares						$ 11.1942
Preferred stock conversion price per share | $ / shares						$ 11.1942