BUSINESS COMBINATION (Details)					3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 01, 2018 USD ($)	Feb. 14, 2018 shares	Sep. 19, 2017 shares	Feb. 27, 2017 USD ($) item $ / shares shares	Jun. 30, 2018 shares	Jun. 30, 2018 USD ($) shares	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) shares
Consideration received upon closing | $	$ 5,000,000
Common stock shares outstanding					63,875,267	63,875,267		48,712,288
Common stock shares sold (in shares)					63,875,267	63,875,267		48,712,288
Issuance of common stock (in shares)		7,500,000	5,292,000
Term loan facility
Credit facility | $				$ 250,000,000
Delayed Draw Feature
Credit facility | $				100,000,000
ABL Member
Credit facility | $				$ 70,000,000
Minimum
Earn out target ( as a percent)				90.00%
Maximum
Earn out target ( as a percent)				100.00%
Private placement
Common stock shares sold (in shares)				419,669
Series A
Proceeds from convertible preferred stock | $							$ (65,000,000)
Senior Debt
Credit facility | $				$ 350,000,000
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc
Common stock shares outstanding				37,715,960
Common stock shares sold (in shares)				37,715,960
Proceeds from convertible preferred stock | $				$ 65,000,000
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | IPO
Common stock shares sold (in shares)				8,342,918
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Private placement
Common stock shares sold (in shares)				2,288,043
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Series A
Proceeds from convertible preferred stock | $						$ 65,000,000
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Series A | Private placement
Proceeds from convertible preferred stock | $				$ 65,000,000
Issuance of common stock (in shares)				650,000
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Earn out provision
Number of trading days | item				20
Number of consecutive trading days				30 days
Number of shares issued					5,000,000
Adjusted EBITDA | $								$ 140,000,000
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Earn out provision | Minimum
Adjusted EBITDA - 2017 | $				$ 140,000,000
Adjusted EBITDA - 2018 | $				170,000,000
Adjusted EBITDA - 2019 | $				$ 200,000,000
Share price - 2017 | $ / shares				$ 12.00
Share price - 2018 | $ / shares				14.00
Share price - 2019 | $ / shares				$ 16.00
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Earn out provision | Maximum
Shares payable annually in 2018				5,000,000
Shares payable annually in 2019				5,000,000
Private Daseke
Number of shares issued				26,665,330
Private Daseke | Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc
Consideration received upon closing | $				$ 266,700,000
Private Daseke | Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Maximum
Value per share issued | $ / shares				$ 10.00
Private Daseke | Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Earn out provision | Maximum
Shares to be issued under earn-out provision				15,000,000
Shares payable annually in 2017				5,000,000