QUARTERLY RESULTS OF CONSOLIDATED OPERATIONS (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended	3 Months Ended										8 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Dec. 31, 2018	Dec. 31, 2019	Apr. 30, 2018	Apr. 30, 2017
Selected Quarterly Financial Information [Abstract]
REVENUE	$ 30,287	$ 45,777	$ 47,436	$ 46,934	$ 45,608	$ 45,638	$ 45,946	$ 44,185	$ 42,716	$ 41,866	$ 40,978	$ 121,871	$ 185,755	$ 169,745	$ 160,104
Net income (loss) attributable to controlling interest	(2,756)	48,658	31,596	3,113	(4,698)	(4,558)	2,916	(20,874)	136,105	12,821	(11,264)	(4,398)	78,669	116,788	43,347
Net income (loss) available to common shareholders	$ (3,892)	$ 46,953	$ 29,891	$ 1,407	$ (6,403)	$ (6,264)	$ 1,211	$ (22,579)	$ 134,331	$ 6,360	$ (13,550)	$ (8,945)	$ 71,848	$ 104,562	$ 31,366
Net income (loss) per common share - basic (in dollars per share)		$ 3.95	$ 2.57	$ 0.11	$ (0.54)							$ (0.75)	$ 6.06	$ 8.71	$ 2.58
Net income (loss) per common share - diluted (in dollars per share)		$ 3.89	$ 2.54	$ 0.11	$ (0.54)							$ (0.75)	$ 6.00	$ 8.71	$ 2.58
Net income (loss) per common share - basic & diluted (in dollars per share)	$ (0.33)					$ (0.52)	$ 0.10	$ (1.89)	$ 11.22	$ 0.53	$ (1.12)