MORTGAGES, NOTES AND LOANS PAYABLE, NET (Narrative) (Details)								6 Months Ended	12 Months Ended
	May 20, 2020 USD ($)	Mar. 27, 2020 USD ($)	Mar. 05, 2020 USD ($)	Jan. 07, 2020 USD ($)	Oct. 17, 2019 USD ($) extention_option	Sep. 21, 2018	Sep. 18, 2018 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) bond	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Feb. 02, 2021 USD ($)	Jun. 30, 2020 USD ($) loan_agreement	Mar. 26, 2020 USD ($)	Mar. 04, 2020 USD ($)	Feb. 28, 2019 USD ($)
Debt Instrument [Line Items]
Amount outstanding								$ 4,320,166,000	$ 4,320,166,000
Special Improvement District bond transfers associated with land sales									$ 10,122,000	$ 22,423,000	$ 10,937,000
Weighted average interest rate								4.34%	4.34%	4.75%
Pledged assets, not separately reported								$ 4,500,000,000	$ 4,500,000,000
Operating Assets
Debt Instrument [Line Items]
Amount outstanding								2,052,295,000	2,052,295,000	$ 2,338,317,000
Self Storage Facility | Operating Assets
Debt Instrument [Line Items]
Amount outstanding													$ 10,900,000
Number of loan agreements | loan_agreement													2
Special Improvement District bonds
Debt Instrument [Line Items]
Special Improvement District bond transfers associated with land sales									10,122,000
Senior Notes due 2029 | Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Aggregate principal amount of debt issued												$ 650,000,000
Interest rate (as a percent)												4.125%
Senior Notes due 2031 | Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Aggregate principal amount of debt issued												$ 650,000,000
Interest rate (as a percent)												4.375%
Senior Notes due 2025 | Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount of debt issued								$ 1,000,000,000	$ 1,000,000,000
Interest rate (as a percent)								5.375%	5.375%
Amount outstanding								$ 1,000,000,000	$ 1,000,000,000	1,000,000,000
Senior Notes due 2025 | Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Debt repurchased												$ 512,500,000
$700 Million Loan Maturity September 2023
Debt Instrument [Line Items]
Aggregate principal amount of debt issued							$ 700,000,000.0
Option to increase borrowing capacity							50,000,000.0
$700 Million Loan Maturity September 2023 | Term Loan
Debt Instrument [Line Items]
Aggregate principal amount of debt issued							615,000,000.0	615,000,000.0	615,000,000.0		$ 615,000,000.0
Debt instrument covered, percent						100.00%
Fixed interest rate						4.61%
$700 Million Loan Maturity September 2023 | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Aggregate principal amount of debt issued							$ 85,000,000.0
Amount outstanding								0	0
The Bridgeland And Woodlands Credit Facility | Term Loan
Debt Instrument [Line Items]
Aggregate principal amount of debt issued					$ 100,000,000.0
The Bridgeland And Woodlands Credit Facility | Line of Credit
Debt Instrument [Line Items]
Extension option, term					1 year
Facility amount					$ 250,000,000.0			250,000,000	250,000,000
Number of extension options | extention_option					2
The Bridgeland And Woodlands Credit Facility | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Aggregate principal amount of debt issued					$ 150,000,000.0
Amount outstanding								50,000,000.0	$ 50,000,000.0
Revolver Loan | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Amount outstanding													$ 61,300,000
One-month LIBOR
Debt Instrument [Line Items]
Interest rate margin (as a percent)									0.14%
One-month LIBOR | $700 Million Loan Maturity September 2023
Debt Instrument [Line Items]
Interest rate margin (as a percent)							1.65%
One-month LIBOR | The Bridgeland And Woodlands Credit Facility | Line of Credit
Debt Instrument [Line Items]
Interest rate margin (as a percent)					2.50%
Creekside Park The Grove | Construction Loans
Debt Instrument [Line Items]
Aggregate principal amount of debt issued				$ 43,400,000
Extension option, term				1 year
Creekside Park The Grove | LIBOR | Construction Loans
Debt Instrument [Line Items]
Interest rate margin (as a percent)				1.75%
Three Hughes Landing
Debt Instrument [Line Items]
Aggregate principal amount of debt issued			$ 61,000,000.0												$ 61,200,000
Extension option, term			12 months
Three Hughes Landing | Operating Assets
Debt Instrument [Line Items]
Amount outstanding								0	$ 0	59,822,000
Three Hughes Landing | One-month LIBOR
Debt Instrument [Line Items]
Interest rate margin (as a percent)			2.60%
Kō'ula | Construction Loans
Debt Instrument [Line Items]
Aggregate principal amount of debt issued		$ 356,800,000
Interest rate margin (as a percent)		3.00%
Extension option, term		1 year
The Woodlands Towers at the Waterway and The Woodlands Warehouse | Bridge Loan
Debt Instrument [Line Items]
Aggregate principal amount of debt issued	$ 280,300,000													$ 137,000,000.0
Extension option, term	6 months
The Woodlands Towers at the Waterway and The Woodlands Warehouse | LIBOR | Bridge Loan
Debt Instrument [Line Items]
Interest rate margin (as a percent)	2.35%
Interest rate margin, extension option	2.90%
1201 Lake Robbins and The Woodlands Warehouse
Debt Instrument [Line Items]
Amount outstanding								280,000,000	$ 280,000,000
Summerlin | Special Improvement District bonds
Debt Instrument [Line Items]
Number of bonds issued | bond									1
Special Improvement District bond transfers associated with land sales									$ 10,100,000
The Woodlands Resort & Conference Center
Debt Instrument [Line Items]
Amount outstanding													$ 62,500,000
The Woodlands Resort & Conference Center | COVID-19
Debt Instrument [Line Items]
Decrease for forgiveness								$ 24,100,000
The Woodlands Resort & Conference Center | Operating Assets
Debt Instrument [Line Items]
Amount outstanding										$ 62,500,000						$ 62,500,000