SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Impact of Topic 606 Adoption on Unaudited Condensed Consolidated Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (3,845)	$ (583)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	26,526	28,418
Cash flows from operating activities:
Accounts receivable	3,490	43,695
Deferred revenue, net	1,130	$ (38,485)
Balances Without Adoption of Topic 606
Cash flows from operating activities:
Net loss	(5,916)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	26,223
Cash flows from operating activities:
Accounts receivable	5,915
Deferred revenue, net	1,079
Accounting Standard Update 2014-09 | Effect of Change Increase / (Decrease)
Cash flows from operating activities:
Net loss	2,071
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	303
Cash flows from operating activities:
Accounts receivable	(2,425)
Deferred revenue, net	$ 51