SUPPLEMENTAL INFORMATION - QUARTERLY FINANCIAL INFORMATION QUARTERLY FINANCIAL INFORMATION (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Total revenues	$ 108,097	$ 163,890	$ 20,097	$ 90,831	$ 168,634	$ 231,100	$ 50,960	$ 144,632	$ 382,915	$ 595,326	$ 856,207
Costs, expenses and other:
Total cost, expenses and other	178,608	179,178	163,379	193,864	152,354	283,047	117,514	106,235	715,029	659,150	632,427
Income from operations	(70,511)	(15,288)	(143,282)	(103,033)	16,280	(51,947)	(66,554)	38,397	(332,114)	(63,824)	223,780
Income (loss) from continuing operations before income taxes	(90,636)	(35,341)	(153,777)	(113,369)	5,274	(62,661)	(76,986)	27,785	(393,123)	(106,588)	177,228
Net income (loss)	$ (55,639)	$ (23,309)	$ (95,450)	$ (71,530)	$ 3,022	$ (41,494)	$ (46,870)	$ 17,062	$ (245,928)	$ (68,280)	$ 155,435
Basic
Net income (loss) attributable to shareholders	$ (0.94)	$ (0.48)	$ (2.04)	$ (1.72)	$ 0.08	$ (1.04)	$ (1.17)	$ 0.47	$ (5.01)	$ (1.74)	$ 4.34
Diluted
Net income (loss) attributable to shareholders	$ (0.94)	$ (0.48)	$ (2.04)	$ (1.72)	$ 0.07	$ (1.04)	$ (1.17)	$ 0.46	$ (5.01)	$ (1.74)	$ 4.24