ACQUISITION - Summary of Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Total Revenues
As reported	$ 354,721	$ 371,483
Pro forma (unaudited)	380,996	451,782
Operating Income
As reported	11,538	8,455
Pro forma (unaudited)	12,633	18,148
Net income (loss) applicable to common shareholders
As reported	30,584	(11,732)
Pro forma (unaudited)	$ 31,009	$ (5,587)
Net income (loss) per share applicable to common shareholders (basic and diluted)
As reported, (in dollars per share)	$ 1.67	$ (0.67)
Pro forma (unaudited) (in dollars per share)	$ 1.70	$ (0.32)