ACQUISITION - Summary of Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Total revenues
As reported		$ 370,683	$ 349,796	$ 1,081,651	$ 1,070,240
Pro forma			423,350	1,107,926	1,296,561
Operating income (loss)
As reported	[1],[2]	17,212	(15,307)	31,739	(13,716)
Pro forma			(5,179)	32,834	17,784
Net loss applicable to common shareholders
As reported		$ (8,521)	(46,562)	(3,304)	(94,899)
Pro forma			$ (39,429)	$ (2,879)	$ (73,542)
Net loss per share applicable to common shareholders (basic and diluted)
As reported, (in dollars per share)		$ (0.46)	$ (2.59)	$ (0.18)	$ (5.32)
Pro forma (unaudited) (in dollars per share)			$ (2.19)	$ (0.16)	$ (4.12)

[1] Deferred tax assets of $14.5 million as of September 30, 2015 were reclassified into liabilities on adoption of ASU 2015-17 - Income Taxes: Balance Sheet Classification of Deferred Taxes.

[2] Unamortized debt issuance costs of $26.8 million as of September 30, 2015 were reclassified from other non-current assets into long-term debt on adoption of ASU 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs.