MORTGAGES, NOTES AND LOANS PAYABLE (Narrative) (Details)															3 Months Ended		9 Months Ended
	Oct. 11, 2018 USD ($)	Sep. 25, 2018 USD ($)	Sep. 21, 2018	Sep. 18, 2018 USD ($)	Sep. 11, 2018 USD ($) extention_option	Jul. 27, 2018 USD ($)	Jul. 20, 2018 USD ($)	Jun. 08, 2018 USD ($) a extention_option	Apr. 30, 2018 USD ($) extention_option	Apr. 13, 2018 USD ($)	Mar. 26, 2018 USD ($)	Jan. 25, 2018 USD ($)	Jan. 19, 2018 USD ($)	Jan. 05, 2018 USD ($) extention_option	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Mortgages, notes and loans payable
Land, buildings and equipment and developments in progress pledged as collateral															$ 4,300,000,000		$ 4,300,000,000
Repayments on mortgage loan																	656,816,000	$ 1,130,337,000
Capitalized debt issuance costs															6,301,000		6,301,000		$ 6,898,000
Loss of extinguishment of debt															0	$ 0	$ 0	$ 46,410,000
Naming and marketing agreement term																	20 years
Settlement of swap liability															1,749,000		$ 1,749,000		$ 5,961,000
Construction Loans | London Interbank Offered Rate (LIBOR)
Mortgages, notes and loans payable
Interest rate margin (as a percent)				1.65%
$700 Million Loan Maturity September 2023
Mortgages, notes and loans payable
Loan amount				$ 700,000,000.0
Option to increase borrowing capacity				50,000,000.0
Percent of loan covered by derivative			100.00%
Derivative fixed interest rate			4.61%
$700 Million Loan Maturity September 2023 | Term Loan
Mortgages, notes and loans payable
Loan amount				615,000,000
6100 Marriweather | Construction Loans
Mortgages, notes and loans payable
Loan amount					$ 89,800,000.0
Number of extension options | extention_option					2
Term of extension option					1 year
6100 Marriweather | Construction Loans | London Interbank Offered Rate (LIBOR)
Mortgages, notes and loans payable
Interest rate margin (as a percent)					2.75%
Columbia Multi-family | Construction Loans
Mortgages, notes and loans payable
Loan amount					$ 85,656,515.000000
Number of extension options | extention_option					2
Term of extension option					1 year
Columbia Multi-family | Construction Loans | London Interbank Offered Rate (LIBOR)
Mortgages, notes and loans payable
Interest rate margin (as a percent)					2.75%
Mortgaged Properties
Mortgages, notes and loans payable
Repayments on mortgage loan																	608,700,000
Capitalized debt issuance costs															8,600,000		8,600,000
Loss of extinguishment of debt																	700,000
Bridgeland Apartments | Construction Loans
Mortgages, notes and loans payable
Loan amount						$ 34,200,000.0
Term of extension option						1 year
Bridgeland Apartments | Construction Loans | London Interbank Offered Rate (LIBOR)
Mortgages, notes and loans payable
Interest rate margin (as a percent)						2.25%
Summerlin Ballpark | Construction Loans
Mortgages, notes and loans payable
Loan amount							$ 51,200,000.0
Summerlin Ballpark | Construction Loans | London Interbank Offered Rate (LIBOR)
Mortgages, notes and loans payable
Interest rate margin (as a percent)							4.92%
250 Water Street
Mortgages, notes and loans payable
Area of land purchased | a								1
Wacker110 N
Mortgages, notes and loans payable
Repayments on mortgage loan													$ 18,900,000
Settlement of swap liability													$ 300,000
Wacker110 N | Construction Loans
Mortgages, notes and loans payable
Loan amount		$ 512,600,000.0							$ 494,500,000.0
Number of extension options | extention_option									2
Term of extension option									1 year
Joint venture debt guaranteed									$ 89,000,000
Increase in joint venture debt guaranteed		$ 92,300,000
Wacker110 N | Construction Loans | London Interbank Offered Rate (LIBOR)
Mortgages, notes and loans payable
Interest rate margin (as a percent)									3.00%
Lakeland Village Center
Mortgages, notes and loans payable
Repayments on mortgage loan										$ 11,800,000
Downtown Summerlin Apartments | Construction Loans
Mortgages, notes and loans payable
Loan amount											$ 44,100,000.0
Term of extension option											3 years
Downtown Summerlin Apartments | Construction Loans | London Interbank Offered Rate (LIBOR)
Mortgages, notes and loans payable
Interest rate margin (as a percent)											2.25%
Lake Woodlands Crossing Retail | Construction Loans
Mortgages, notes and loans payable
Loan amount												$ 15,500,000.0
Interest rate margin (as a percent)												1.80%
Maximum recourse percentage upon achievement of conditions												50.00%
Recourse percentage												15.00%
Occupancy percentage												90.00%
Three Hughes Landing
Mortgages, notes and loans payable
Number of extension options | extention_option														2
Term of extension option														1 year
Long-term line of credit														$ 65,500,000
Three Hughes Landing | One Month LIBOR
Mortgages, notes and loans payable
Interest rate margin (as a percent)														2.60%
MPC | Summerlin | Special Improvement District bonds
Mortgages, notes and loans payable
New SIDs issued															0		0
Bond obligation															$ 10,500,000		10,500,000
Subsequent Event | Two Lakes Edge | Construction Loans
Mortgages, notes and loans payable
Loan amount	$ 74,000,000.0
Term of extension option	1 year
Subsequent Event | Two Lakes Edge | Construction Loans | London Interbank Offered Rate (LIBOR)
Mortgages, notes and loans payable
Interest rate margin (as a percent)	2.15%
Notes Payable, Other Payables | 250 Water Street
Mortgages, notes and loans payable
Number of extension options | extention_option								3
Term of extension option								6 months
Note payable to acquire land								$ 129,700,000
Interest free term								6 months
Interest rate (as a percent)								6.00%
Minimum paydown for term extension								$ 30,000,000
Revolving Credit Facility | $700 Million Loan Maturity September 2023 | Line of Credit
Mortgages, notes and loans payable
Loan amount				$ 85,000,000.0
Naming Rights And Marketing Agreement
Mortgages, notes and loans payable
Revenue from naming and marketing agreement																	$ 4,000,000