SEGMENTS (Summary of Segment Operating Results) (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segments reporting
Number of reportable segments | segment			3
Total revenues	$ 257,160	$ 258,736	$ 599,844	$ 799,137
Total operating expenses	211,138	234,441	559,844	676,280
Operating income before other items	46,022	24,295	40,000	122,857
Depreciation and amortization	(31,123)	(35,899)	(88,398)	(96,193)
Other (loss) income, net	(3,710)	(160)	(3,444)	750
Equity in earnings from real estate and other affiliates	8,612	7,467	39,297	25,821
Gains on sales of properties	0	237	0	32,452
Segment EBT	31,334	16,362	25,430	51,141
Net income	23,847	10,516	19,802	19,295
Net income attributable to noncontrolling interests	(482)	(12)	(51)	(12)
Net income attributable to common stockholders	23,365	10,504	19,751	19,283
Operating Segments
Segments reporting
Total revenues	257,160	258,736	599,844	799,137
Total operating expenses	149,318	170,140	363,002	501,574
Operating income before other items	107,842	88,596	236,842	297,563
Depreciation and amortization	(28,880)	(33,979)	(82,085)	(90,342)
Interest (expense) income, net	(7,946)	(2,602)	(14,800)	(9,781)
Other (loss) income, net	(3,319)	(127)	(2,782)	(128)
Equity in earnings from real estate and other affiliates	8,609	7,467	39,294	25,821
Gains on sales of properties	0	237	0	32,452
Segment EBT	76,306	59,592	176,469	255,585
Operating Segments | Operating
Segments reporting
Total revenues	101,000	79,533	285,481	243,498
Total operating expenses	59,779	41,837	149,169	123,879
Operating income before other items	41,221	37,696	136,312	119,619
Depreciation and amortization	(28,329)	(33,885)	(79,190)	(88,918)
Interest (expense) income, net	(18,891)	(15,940)	(52,886)	(46,004)
Other (loss) income, net	(2,887)	(249)	(2,723)	(265)
Equity in earnings from real estate and other affiliates	(529)	317	1,056	3,739
Gains on sales of properties	0	0	0	0
Segment EBT	(9,415)	(12,061)	2,569	(11,829)
Operating Segments | MPC
Segments reporting
Total revenues	143,135	64,929	261,665	211,711
Total operating expenses	70,237	37,223	143,608	113,171
Operating income before other items	72,898	27,706	118,057	98,540
Depreciation and amortization	(79)	(76)	(245)	(247)
Interest (expense) income, net	6,626	6,355	19,826	17,902
Other (loss) income, net	18	0	18	0
Equity in earnings from real estate and other affiliates	9,454	6,480	34,682	21,552
Gains on sales of properties	0	0	0	0
Segment EBT	88,917	40,465	172,338	137,747
Operating Segments | Strategic
Segments reporting
Total revenues	13,025	114,274	52,698	343,928
Total operating expenses	19,302	91,080	70,225	264,524
Operating income before other items	(6,277)	23,194	(17,527)	79,404
Depreciation and amortization	(472)	(18)	(2,650)	(1,177)
Interest (expense) income, net	4,319	6,983	18,260	18,321
Other (loss) income, net	(450)	122	(77)	137
Equity in earnings from real estate and other affiliates	(316)	670	3,556	530
Gains on sales of properties	0	237	0	32,452	$ 32,500
Segment EBT	(3,196)	31,188	1,562	129,667
Property damage repair charge			13,400
Corporate expenses and other items
Segments reporting
Corporate expenses and other items	$ 52,459	$ 49,076	$ 156,667	$ 236,290