STOCKHOLDERS’ EQUITY (Details)									1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 20, 2017 shares	Sep. 19, 2017 USD ($) $ / shares shares	Jul. 28, 2017 $ / shares	Jul. 18, 2017 $ / shares	Apr. 24, 2017 $ / shares	Feb. 27, 2017 USD ($) shares	Feb. 21, 2017 $ / shares	Oct. 13, 2016 $ / shares	Feb. 28, 2017 shares	Sep. 30, 2017 USD ($) $ / shares shares	Sep. 30, 2016 USD ($) $ / shares	Sep. 30, 2017 USD ($) item $ / shares shares	Sep. 30, 2016 USD ($) $ / shares	Dec. 31, 2016 USD ($)
Issuance of common stock (in shares)		5,292,000										5,675,967
Common stock par value | $ / shares		$ 0.00010
Proceeds from Issuance of Convertible Preferred Stock | $												$ 65,000,000
Issuance of common stock | $		$ 63,600,000										$ 74,686,000
Warrants
Shares that can be purchased out of each warrant										0.50		0.50
Exercise price per half share | $ / shares												$ 5.75
Exercise price per whole share | $ / shares										$ 11.50		$ 11.50
Number of fractional shares to be issued												0
Total number of warrants outstanding										35,040,664		35,040,664
Share issued for exercise of warrants (in shares)										17,520,332		17,520,332
Expiration term of public warrants												5 years
Public Warrants
Total number of warrants outstanding										19,959,908		19,959,908
Warrants exercisable period												30 days
Number of trading days in which the price per share should equals or exceeds $24.00 per share to call the Public Warrants for redemption | item												20
Redemption price per warrant | $												$ 0.01
Redemption price per warrant subject to stated common stock value | $ / shares												$ 24.00
Number of trading days in which the price per share should equals or exceeds $24.00 per share to call the Public Warrants for redemption | item												20
Private Warrants
Total number of warrants outstanding										15,080,756		15,080,756
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc
Proceeds from Issuance of Convertible Preferred Stock | $						$ 65,000,000
IPO
Issuance of common stock (in shares)		4,882,167
Selling Stockholders
Issuance of common stock (in shares)		409,833
Gross selling price to public | $ / shares		$ 12.00
Net selling price to public | $ / shares		$ 11.34
Underwriting agreement
Issuance of common stock (in shares)	793,800
Duration to purchase additional shares	30 days
Series A
Initial conversion rate per share										8.6957		8.6957
Initial conversion rate per share | $ / shares										$ 11.50		$ 11.50
Number of years of anniversary from issue date for holder elects to convert (in years)												7 years
Number of consecutive trading days at option by delivery of Notice of Conversion (in days)												10 days
Number of consecutive trading days commencing on trading day immediately following notice (in days)												20 days
Shares would be issuable upon conversion of currently outstanding shares (in shares)												5,652,171
Minimum percentage of weighted average price of common stock under preferred stock conversion on or after third anniversary (as a percent)												140.00%
Minimum trading days of weighted average price of common stock under preferred stock conversion on or after third anniversary (in days)												20 days
Maximum trading days of weighted average price of common stock under preferred stock conversion on or after third anniversary (in days)												30 days
Minimum percentage of weighted average price of common stock under preferred stock conversion on or after fifth anniversary (as a percent)												115.00%
Minimum trading days of weighted average price of common stock under preferred stock conversion on or after fifth anniversary (in days)												20 days
Maximum trading days of weighted average price of common stock under preferred stock conversion on or after fifth anniversary (in days)												30 days
Minimum trading days of weighted average price of common stock under preferred stock conversion on or after seventh anniversary (in days)												10 days
Maximum days for conversion of preferred stock into common stock due to fundamental changes (in days)												15 days
Base price for calculation of conversion rate | $ / shares												$ 100.00
Percentage of closing sale price of common stock										66.67%		66.67%
Minimum percentage of shares of common stock owned by holder for limitation in preferred stock												9.99%
Maximum percentage of shares can be converted to common stock												19.99%
Preferred share liquidation amount per share | $ / shares										$ 100		$ 100
Dividend rate (as a percent)										7.625%		7.625%
Preferred Stock, Dividends Per Share, Declared (in dollars per share) | $ / shares				$ 1.91	$ 0.68					$ 1.91		$ 2.59
Dividend paid (in dollars per share) | $ / shares			$ 0.68
Accrued convertible preferred dividends | $										$ 1,239,000		$ 1,239,000
Preferred stock dividend rate										7.625%		7.625%
Series A | Accrued expenses and other liabilities
Accrued convertible preferred dividends | $										$ 1,200,000		$ 1,200,000
Series A | Maximum
Number of business days following tenth consecutive trading day to convert shares (in days)												5 days
Number of trading days from receipt of Notice of Conversion (in days)												2 days
Series A | Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc
Issuance of common stock (in shares)												650,000
Proceeds from Issuance of Convertible Preferred Stock | $												$ 65,000,000
Series A | Private placement | Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc
Issuance of common stock (in shares)						650,000
Proceeds from Issuance of Convertible Preferred Stock | $						$ 65,000,000
Series B
Preferred Stock, Dividends Per Share, Declared (in dollars per share) | $ / shares							$ 12.50	$ 18.75			$ 18.75	$ 12.50	$ 18.75
Accrued convertible preferred dividends | $											$ 1,378,000		$ 1,378,000
Conversion of Convertible Stock to common shares (in shares)									9,301,150
Series B | Accrued expenses and other liabilities
Accrued convertible preferred dividends | $														$ 1,200,000