STOCKHOLDERS' EQUITY (Details) $ / shares in Units, $ in Millions							3 Months Ended		6 Months Ended
	May 20, 2020 $ / shares	Mar. 15, 2020 $ / shares	Feb. 27, 2020 $ / shares	May 21, 2019 $ / shares	Mar. 15, 2019 $ / shares	Feb. 27, 2019 $ / shares	Jun. 30, 2020 Vote $ / shares shares	Jun. 30, 2019 $ / shares	Jun. 30, 2020 USD ($) D Vote $ / shares shares	Jun. 30, 2019 $ / shares	Dec. 31, 2019 $ / shares
Number of votes for each common stock | Vote							1		1
Shares of common stock reserved for future issuance | shares							0		0
Common stock, par value | $ / shares							$ 0.0001		$ 0.0001		$ 0.0001
Number of years of anniversary from issue date for holder elects to convert (in years)									7 years
2017 Omnibus Incentive Plan
Shares of common stock reserved for future issuance | shares							0		0
Warrants
Total number of warrants outstanding | shares							35,040,658		35,040,658
Share issued for exercise of warrants (in shares) | shares							17,520,329		17,520,329
Shares that can be purchased out of each warrant | shares							0.50		0.50
Exercise price per half share (in dollars per share) | $ / shares									$ 5.75
Exercise price per whole share (in dollars per share) | $ / shares							$ 11.50		$ 11.50
Number of fractional shares to be issued | shares									0
Expiration term of public warrants									5 years
Public Warrants
Total number of warrants outstanding | shares							19,959,902		19,959,902
Redemption price per warrant | $ / shares									$ 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 | D									20
Warrants exercisable period									30 days
Private Placement Warrants
Total number of warrants outstanding | shares							15,080,756		15,080,756
Series A
Preferred stock, par value | $ / shares							$ 0.0001		$ 0.0001
Number of shares of the company's stock issued upon initial conversion | shares							8.6957		8.6957
Initial conversion rate per share (in dollars per share) | $ / shares							$ 11.50		$ 11.50
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) | shares									5,652,173
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%	7.625%	7.625%
Preferred stock, quarterly dividend declared (in dollars per share) | $ / shares	$ 1.91		$ 1.91	$ 1.91		$ 1.91	$ 1.91	$ 1.91	$ 3.81	$ 3.81
Dividend paid (in dollars per share) | $ / shares		$ 1.91			$ 1.91
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
Preferred stock, issued (in shares) | shares							650,000		650,000
Proceeds from convertible preferred stock | $									$ 65.0