SEGMENTS (Summary of Segment Operating Results) (Details) ft² in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) ft²	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) ft² segment location	Sep. 30, 2018 USD ($)
Segments reporting
Number of reportable segments | segment			4
Total revenues	$ 231,172,000	$ 257,160,000	$ 1,016,378,000	$ 599,844,000
Total operating expenses	(210,071,000)	(211,138,000)	(918,446,000)	(559,844,000)
Depreciation and amortization	(40,093,000)	(31,123,000)	(115,142,000)	(88,398,000)
Interest (expense) income, net	0		200,000
Other (loss) income, net	1,337,000	(3,710,000)	11,798,000	(3,444,000)
Equity in earnings (losses) from real estate and other affiliates	4,542,000	8,612,000	20,847,000	39,297,000
Selling profit from sales-type leases	13,537,000		13,537,000
Gain (loss) on sale or disposal of real estate	24,201,000	0	24,051,000	0
Segment EBT	38,761,000	31,334,000	99,503,000	25,430,000
Net income	30,043,000	23,847,000	75,296,000	19,802,000
Net income attributable to noncontrolling interests	(285,000)	(482,000)	(240,000)	(51,000)
Net income attributable to common stockholders	29,758,000	23,365,000	75,056,000	19,751,000
Operating Assets
Segments reporting
Total revenues	104,223,000	87,462,000	305,395,000	264,017,000
Master Planned Communities
Segments reporting
Total revenues	$ 92,287,000	143,135,000	$ 216,042,000	261,665,000
Seaport District
Segments reporting
Area of real estate property (in sqft) | ft²	450		450
Number of primary locations | location			3
Operating locations | location			2
Total revenues	$ 23,130,000	14,601,000	$ 43,051,000	22,612,000
Strategic Developments
Segments reporting
Total revenues	11,515,000	11,962,000	451,873,000	51,550,000
Operating Segments
Segments reporting
Total revenues	231,155,000	257,160,000	1,016,361,000	599,844,000
Total operating expenses	(131,776,000)	(149,152,000)	(695,740,000)	(362,837,000)
Segment operating income	99,379,000	108,008,000	320,621,000	237,007,000
Depreciation and amortization	(37,769,000)	(29,329,000)	(109,323,000)	(83,429,000)
Interest (expense) income, net	(15,077,000)	(7,946,000)	(35,260,000)	(14,800,000)
Other (loss) income, net	951,000	(3,319,000)	2,304,000	(2,782,000)
Equity in earnings (losses) from real estate and other affiliates	4,542,000	8,611,000	20,847,000	39,294,000
Selling profit from sales-type leases	13,537,000	0	13,537,000	0
Gain (loss) on sale or disposal of real estate	24,201,000	0	24,051,000	0
Segment EBT	89,764,000	76,025,000	236,777,000	175,290,000
Operating Segments | Operating Assets
Segments reporting
Total revenues	104,223,000	87,462,000	305,395,000	264,017,000
Total operating expenses	(47,950,000)	(43,373,000)	(139,589,000)	(126,372,000)
Segment operating income	56,273,000	44,089,000	165,806,000	137,645,000
Depreciation and amortization	(28,844,000)	(26,470,000)	(84,890,000)	(74,028,000)
Interest (expense) income, net	(21,645,000)	(18,891,000)	(60,695,000)	(52,886,000)
Other (loss) income, net	63,000	(2,767,000)	1,186,000	(2,603,000)
Equity in earnings (losses) from real estate and other affiliates	441,000	(76,000)	3,195,000	1,507,000
Selling profit from sales-type leases	13,537,000	0	13,537,000	0
Segment EBT	19,825,000	(4,115,000)	38,139,000	9,635,000
Operating Segments | Master Planned Communities
Segments reporting
Total revenues	92,287,000	143,135,000	216,042,000	261,665,000
Total operating expenses	(45,169,000)	(70,237,000)	(114,075,000)	(143,608,000)
Segment operating income	47,118,000	72,898,000	101,967,000	118,057,000
Depreciation and amortization	(88,000)	(78,000)	(334,000)	(245,000)
Interest (expense) income, net	8,550,000	6,626,000	24,376,000	19,826,000
Other (loss) income, net	534,000	18,000	601,000	18,000
Equity in earnings (losses) from real estate and other affiliates	4,523,000	9,454,000	18,859,000	34,682,000
Segment EBT	60,637,000	88,918,000	145,469,000	172,338,000
Operating Segments | Seaport District
Segments reporting
Total revenues	23,130,000	14,601,000	43,051,000	22,612,000
Total operating expenses	(27,330,000)	(21,989,000)	(59,735,000)	(31,965,000)
Segment operating income	(4,200,000)	(7,388,000)	(16,684,000)	(9,353,000)
Depreciation and amortization	(6,767,000)	(2,309,000)	(19,713,000)	(6,506,000)
Interest (expense) income, net	(4,984,000)	1,471,000	(8,440,000)	8,466,000
Other (loss) income, net	0	(120,000)	(147,000)	(120,000)
Equity in earnings (losses) from real estate and other affiliates	(705,000)	(452,000)	(1,788,000)	(692,000)
Gain (loss) on sale or disposal of real estate	0	0	(6,000)	0
Segment EBT	(16,656,000)	(8,798,000)	(46,778,000)	(8,205,000)
Operating Segments | Strategic Developments
Segments reporting
Total revenues	11,515,000	11,962,000	451,873,000	51,550,000
Total operating expenses	(11,327,000)	(13,553,000)	(382,341,000)	(60,892,000)
Segment operating income	188,000	(1,591,000)	69,532,000	(9,342,000)
Depreciation and amortization	(2,070,000)	(472,000)	(4,386,000)	(2,650,000)
Interest (expense) income, net	3,002,000	2,848,000	9,499,000	9,794,000
Other (loss) income, net	354,000	(450,000)	664,000	(77,000)
Equity in earnings (losses) from real estate and other affiliates	283,000	(315,000)	581,000	3,797,000
Gain (loss) on sale or disposal of real estate	24,201,000	0	24,057,000	0
Segment EBT	25,958,000	20,000	99,947,000	1,522,000
Corporate expenses and other items
Segments reporting
Corporate income, expenses and other items	$ (59,721,000)	$ (52,178,000)	$ (161,481,000)	$ (155,488,000)
Tin Building | Seaport District
Segments reporting
Area of real estate property (in sqft) | ft²	53		53