EARNINGS PER COMMON SHARE (Calculation of EPS) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earning Per Share [Line Items]
Net income/(loss) from continuing operations					$ 64,678,000	$ (52,855,000)	$ (4,184,000)	$ (8,698,000)	$ 55,978,000	$ (1,059,000)	$ 80,565,000
Participaint securities, continuing operations									21,000	0	44,000
Net (Loss)/Income from Discontinued Operations					(340,153,000)	(45,884,000)	34,045,000	59,437,000	0	(292,555,000)	203,395,000
Participating securities, discontinued operations									0	20,000	110,000
Net income/(loss)	$ 53,645,000	$ (6,307,000)	$ 3,211,000	$ 5,429,000	$ (275,475,000)	$ (98,739,000)	$ 29,861,000	$ 50,739,000	55,978,000	(293,614,000)	283,960,000
Common Class A [Member]
Earning Per Share [Line Items]
Net income/(loss) from continuing operations									55,957,000	(1,002,000)	79,424,000
Net (Loss)/Income from Discontinued Operations									$ 0	$ (295,001,000)	$ 200,515,000
Weighted average common shares outstanding:
Weighted average common shares outstanding, basic									87,834,769	90,949,577	95,584,559
Weighted average common shares outstanding, diluted									88,082,978	90,949,577	95,629,090
Common Class B [Member]
Earning Per Share [Line Items]
Net income/(loss) from continuing operations									$ 0	$ (57,000)	$ 1,097,000
Net (Loss)/Income from Discontinued Operations									$ 0	$ 2,426,000	$ 2,770,000
Weighted average common shares outstanding:
Weighted average common shares outstanding, basic									0	533,758	1,320,337
Weighted average common shares outstanding, diluted									0	533,758	1,320,337