Retirement Plan	12 Months Ended
Dec. 31, 2016
Postemployment Benefits [Abstract]
Retirement Plan	10. Retirement Plan In February 2015, the Company established a defined-contribution retirement plan under Section 401(k) of the Internal Revenue Code (the 401(k) Plan). The 401(k) Plan covers all employees who meet defined minimum age and service requirements, and allows participants to defer a portion of their annual compensation. The Company matches employee deferrals up to 5.75 percent of eligible compensation. For the years ended December 31, 2016 and 2015, the Company contributed $0.6 million and $0.2 million, respectively, in matching contributions to the 401(k) Plan. Prior to the establishment of the 401(k) Plan in February 2015, the Company did not sponsor any retirement plans.

Retirement Plan

12 Months Ended

Dec. 31, 2016

10. Retirement Plan

In February 2015, the Company established a defined-contribution retirement plan under Section 401(k) of the Internal Revenue Code (the 401(k) Plan). The 401(k) Plan covers all employees who meet defined minimum age and service requirements, and allows participants to defer a portion of their annual compensation. The Company matches employee deferrals up to 5.75 percent of eligible compensation. For the years ended December 31, 2016 and 2015, the Company contributed $0.6 million and $0.2 million, respectively, in matching contributions to the 401(k) Plan. Prior to the establishment of the 401(k) Plan in February 2015, the Company did not sponsor any retirement plans.