BUSINESS COMBINATION Cash Proceeds (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		6 Months Ended
	Feb. 14, 2018	Sep. 19, 2017	Feb. 27, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 01, 2018	Dec. 31, 2017
Proceeds from issuance of common stock	$ 84,600	$ 63,600				$ 84,569	$ 64,577
Repayment of debt						$ 25,227	$ 224,587
Common stock shares sold (in shares)						63,875,267			48,712,288
Common stock shares outstanding						63,875,267			48,712,288
Shares outstanding value (par value)						$ 0.0001		$ 0.0001	$ 0.0001
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc
Proceeds from issuance of common stock			$ 83,429
Issuance of convertible preferred stock			65,000
Proceeds from Term Loan Facility			250,000
Cash(2)			3,209
Total proceeds			401,638
Payment of deferred financing fees (7)			14,148
Hennessy transaction costs			19,063
Daseke transaction costs(9)			1,204	$ 400	$ 800
Total use of proceeds			366,972
Net cash received			$ 34,666
Common stock shares sold (in shares)			37,715,960
Common stock shares outstanding			37,715,960
Shares outstanding value (par value)			$ 10.00
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Main Street Capital Corporation and Prudential Capital Partners
Repayment of debt			$ 36,168
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Interest Expense
Excludes fees paid subsequent to closing			81
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Line of credit
Repayment of debt			16,717
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Line of credit | Interest Expense
Payment of accrued interest			59
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Senior term loan
Repayment of debt			122,724
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Senior term loan | Interest Expense
Payment of accrued interest			422
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Equipment term loans
Repayment of debt			89,488
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Equipment term loans | Interest Expense
Payment of accrued interest			731
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Subordinated notes
Repayment of debt			67,460
Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc | Subordinated notes | Interest Expense
Payment of accrued interest			$ 745
IPO | Hennessy Capital Acquisition Corp II and HCAC Merger Sub Inc
Common stock shares sold (in shares)			8,342,918