Stock-Based Compensation - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017 USD ($) Period $ / shares	Jan. 01, 2017 shares	Jan. 01, 2016 shares	Apr. 28, 2015 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of stock options granted to employees | $ / shares	$ 0.88
Options outstanding and exercisable, aggregate intrinsic value | $	$ 0
Excess tax benefit from stock-based awards | $	$ 0
2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock reserved for issuance				1,527,770
Additional number of shares of common stock reserved for issuance		728,835	338,930
Common stock reserved for issuance, description	Initially, a total of 1,527,770 shares of the Company’s common stock were reserved for issuance pursuant to the 2014 Plan, which number is also the limit on shares of common stock available for awards of incentive stock options. The number of shares available for issuance under the 2014 Plan will, unless otherwise determined by the Company’s Board of Directors or the Compensation Committee, be automatically increased on January 1st of each year commencing on January 1, 2016 and ending on (and including) January 1, 2024, in an amount equal to 3.5% of the total number of shares of the Company’s common stock outstanding on December 31st of the preceding calendar year.
Percentage of common stock outstanding to increase shares reserved for issuance	3.50%
2014 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock reserved for issuance				458,331
Additional number of shares of common stock reserved for issuance		208,238	96,837
Common stock reserved for issuance, description	The number of shares available for issuance under the ESPP will, unless otherwise determined by the Company’s Board of Directors or the Compensation Committee, be automatically increased on January 1st of each year commencing on January 1, 2016 and ending on (and including) January 1, 2024, in an amount equal to 1% of the total number of shares of the Company’s common stock outstanding on December 31st of the preceding calendar year.
Percentage of common stock outstanding to increase shares reserved for issuance	1.00%
Duration of employee stock purchase plan as determined by the compensation committee	24 months
Duration for offering period, employee stock purchase plan	6 months
Employee stock purchase plan, number of purchase periods | Period	4
Maximum duration for purchase under employee stock purchase plan	1 year
Maximum duration of employee stock purchase plan	27 months
Percentage of purchase of common stock	85.00%
Percentage of common stock on the date of purchase	85.00%