SIGNIFICANT ACCOUNTING POLICIES - (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) lease	Mar. 31, 2019 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 5,773
Increase to allowance based on a percent of Current Quarter revenue	556
Adjustment based on aged receivable analysis	1,829
Charge-offs	(1,022)
Balance at end of period	7,136
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of Current Period	1,527
Accretion expense, included in depreciation and amortization expense	31
Disposals	(219)
Payments	(64)
Balance at end of Current Period	$ 1,275
Lessor Income
Number of Operating Leases | lease	3
Number of subleases | lease	13
Lessor income	$ 116	$ 111
Sublease income	$ 401	373
Defined Contribution Plan
401(k) match expense		$ 1,300