SEGMENTS (Summary of Segment Operating Results) (Details) ft² in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) ft²	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) ft² segment location	Jun. 30, 2019 USD ($)
Segments reporting
Number of reportable segments | segment			4
Total revenues	$ 156,173	$ 431,316	$ 331,348	$ 785,206
Depreciation and amortization	(46,963)	(38,918)	(108,600)	(75,049)
Other income, net	1,607	10,288	(2,077)	10,461
Equity in (losses) earnings from real estate and other affiliates	(8,552)	6,354	2,797	16,305
Gain on sale or disposal of real estate	8,000	(144)	46,124	(150)
Provision for impairment	0	0	(48,738)	0
Segment EBT	(40,947)	17,801	(200,129)	60,742
Net (loss) income	(34,103)	13,328	(159,185)	45,253
Net income (loss) attributable to noncontrolling interests	19	149	(33)	45
Net (loss) income attributable to common stockholders	(34,084)	13,477	(159,218)	45,298
Operating Assets
Segments reporting
Total revenues	84,277	109,219	198,534	201,172
Master Planned Communities
Segments reporting
Total revenues	$ 68,913	72,859	$ 119,359	123,755
Seaport District
Segments reporting
Area of real estate property (in sqft) | ft²	453		453
Number of primary locations | location			3
Operating locations | location			2
Strategic Developments
Segments reporting
Total revenues	$ 624	236,347	$ 1,384	440,358
Operating Segments
Segments reporting
Total revenues	156,086	431,316	331,243	785,206
Total operating expenses	(95,173)	(330,323)	(289,745)	(561,037)
Segment operating income	60,913	100,993	41,498	224,169
Depreciation and amortization	(45,512)	(37,037)	(105,328)	(71,554)
Interest (expense) income, net	(18,369)	(10,465)	(39,130)	(20,183)
Other income, net	1,485	716	(2,317)	1,353
Equity in (losses) earnings from real estate and other affiliates	(8,552)	6,354	2,797	16,305
Gain on sale or disposal of real estate	8,000	(144)	46,124	(150)
Segment EBT	(2,035)	60,417	(105,094)	149,940
Operating Segments | Operating Assets
Segments reporting
Total revenues	84,277	109,219	198,534	201,172
Total operating expenses	(42,222)	(48,727)	(94,462)	(91,639)
Segment operating income	42,055	60,492	104,072	109,533
Depreciation and amortization	(36,995)	(28,938)	(74,084)	(56,046)
Interest (expense) income, net	(23,103)	(20,059)	(49,296)	(39,050)
Other income, net	226	1,088	167	1,123
Equity in (losses) earnings from real estate and other affiliates	475	45	4,869	2,754
Gain on sale or disposal of real estate	0	0	38,124	0
Provision for impairment	0	0	(48,738)	0
Segment EBT	(17,342)	12,628	(24,886)	18,314
Operating Segments | Master Planned Communities
Segments reporting
Total revenues	68,913	72,859	119,359	123,755
Total operating expenses	(31,970)	(38,913)	(55,692)	(65,979)
Segment operating income	36,943	33,946	63,667	57,776
Depreciation and amortization	(91)	(86)	(182)	(246)
Interest (expense) income, net	8,303	8,283	16,857	15,826
Other income, net	0	72	0	67
Equity in (losses) earnings from real estate and other affiliates	(2,968)	6,499	5,966	14,336
Segment EBT	42,187	48,714	86,308	87,759
Operating Segments | Seaport District
Segments reporting
Total revenues	2,272	12,891	11,966	19,921
Total operating expenses	(8,464)	(17,972)	(22,775)	(32,405)
Segment operating income	(6,192)	(5,081)	(10,809)	(12,484)
Depreciation and amortization	(6,776)	(6,753)	(27,651)	(12,946)
Interest (expense) income, net	(4,626)	(1,924)	(9,679)	(3,456)
Other income, net	(409)	(61)	(3,777)	(147)
Equity in (losses) earnings from real estate and other affiliates	(6,633)	(451)	(8,676)	(1,083)
Gain on sale or disposal of real estate	0	0	0	(6)
Segment EBT	(24,636)	(14,270)	(60,592)	(30,122)
Operating Segments | Strategic Developments
Segments reporting
Total revenues	624	236,347	1,384	440,358
Total operating expenses	(12,517)	(224,711)	(116,816)	(371,014)
Segment operating income	(11,893)	11,636	(115,432)	69,344
Depreciation and amortization	(1,650)	(1,260)	(3,411)	(2,316)
Interest (expense) income, net	1,057	3,235	2,988	6,497
Other income, net	1,668	(383)	1,293	310
Equity in (losses) earnings from real estate and other affiliates	574	261	638	298
Gain on sale or disposal of real estate	8,000	(144)	8,000	(144)
Segment EBT	(2,244)	13,345	(105,924)	73,989
Corporate expenses and other items
Segments reporting
Corporate income, expenses and other items	$ (32,068)	(47,089)	$ (54,091)	(104,687)
Tin Building | Seaport District
Segments reporting
Area of real estate property (in sqft) | ft²	53		53
Hospitality Revenue | Operating Segments | Operating Assets
Segments reporting
Total revenues	$ 2,500	25,600	$ 19,800	48,500
Total operating expenses	$ (4,400)	$ (16,600)	$ (17,200)	$ (32,200)