Stock-Based Compensation - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Share-based Compensation
Total grant date fair value of options vested	$ 797,000	$ 173,000	$ 904,000	$ 276,000
Number of stock options granted			197,950
Shares available for future issuance (in shares)	329,331		329,331		342,500
Total unrecognized compensation expense related to unvested options	$ 3,000,000		$ 3,000,000
Unrecognized compensation expense, weighted-average period expected to be recognized			2 years 9 months 18 days
Options remained outstanding	1,268,665		1,268,665		1,414,730
Weighted-average exercise price (per share)	$ 5.76		$ 5.76		$ 5.28
Stock-based compensation expense	$ 408,000	100,000	$ 839,000	211,000
Employees
Share-based Compensation
Weighted-average grant date fair value of options granted	$ 5.25		$ 4.67
Stock-based compensation expense	$ 319,000	96,000	$ 740,000	$ 201,000
Non-Employee
Share-based Compensation
Number of stock options granted			0	0
Options remained outstanding	35,568		35,568
Weighted-average exercise price (per share)	$ 4.80		$ 4.80
Stock-based compensation expense	$ 89,000	$ 4,000	$ 99,000	$ 10,000
2016 Employee Incentive Plan
Share-based Compensation
Maximum number of common stock shares may be issued under the plan	500,000		500,000
Annual increases in the number of shares available for issuance, percentage of outstanding capital stock			3.00%
2016 Employee Stock Purchase Plan
Share-based Compensation
Maximum number of common stock shares may be issued under the plan	96,153		96,153
Annual increases in the number of shares available for issuance, percentage of outstanding capital stock			1.00%
Shares available for future issuance (in shares)	78,229		78,229
Number of shares issued (in shares)			17,924
Value of share issued			$ 122,000