LONG-TERM DEBT - Additional information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2013	Dec. 31, 2016	Oct. 29, 2016	Apr. 26, 2016	Feb. 19, 2015
Long-term Debt and Capital Lease Obligations, Including Current Maturities [Abstract]
2017	$ (14,309,000)
2018	(14,041,000)
2019	(12,962,000)
2020	(7,944,000)
2021	(4,378,000)
Thereafter	(241,550,000)
Loan amount attributable to interest	(434,000)
Total	266,466,000		$ 281,673,000
Total (Present value of minimum lease payments on capital leases)	294,750,000
Senior Debt
Long-term Debt and Capital Lease Obligations, Including Current Maturities [Abstract]
2017	(2,500,000)
2018	(2,500,000)
2019	(2,500,000)
2020	(2,500,000)
2021	(2,500,000)
Thereafter	(237,500,000)
Total (Present value of minimum lease payments on capital leases)	250,000,000
Equipment term loans
Loan amount					$ 8,800,000	$ 7,800,000
Interest rate (as a percent)				3.25%
Long-term Debt and Capital Lease Obligations, Including Current Maturities [Abstract]
2017	(9,359,000)
2018	(9,696,000)
2019	(9,365,000)
2020	(5,138,000)
2021	(1,825,000)
Thereafter	(4,050,000)
Total (Present value of minimum lease payments on capital leases)	39,433,000
Capital leases
Long-term Debt and Capital Lease Obligations, Including Current Maturities [Abstract]
2017	(2,450,000)
2018	(1,845,000)
2019	(1,097,000)
2020	(306,000)
2021	(53,000)
Total minimum lease payments	5,751,000
Loan amount attributable to interest	(434,000)
Total	5,317,000
Less current portion	(2,272,000)
Long-term capital leases	3,045,000
Senior subordinated secured debt | Main Street Capital Corporation
Loan amount		$ 20,000,000
Interest rate (as a percent)		12.00%
Paid-in-kind interest (as a percent)		2.50%
Accrued, Paid-in-kind interest added to principal balance	100,000		500,000
Accrued, Paid-in-kind, interest			100,000
Senior subordinated secured debt | Prudential Capital Partners
Loan amount		$ 20,000,000
Interest rate (as a percent)		12.00%
Paid-in-kind interest (as a percent)		2.50%
Accrued, Paid-in-kind interest added to principal balance	$ 100,000		500,000
Accrued, Paid-in-kind, interest			$ 100,000
Subordinated Debt.
Make-whole payment	5.00%
Subordinated Debt. | LST Seller notes
Loan amount	$ 22.0
Interest rate (as a percent)	10.00%
Subordinated Debt. | DTR Seller notes
Loan amount	$ 1.0
Interest rate (as a percent)	5.00%
Subordinated Debt. | BHE Seller notes
Loan amount	$ 2.0
Interest rate (as a percent)	7.00%