Mortgages, Notes and Loans Payable, Net (Activity in Borrowings) (Details) - USD ($)							3 Months Ended		9 Months Ended
	Sep. 30, 2020	Jun. 22, 2020	May 20, 2020	Mar. 26, 2020	Mar. 13, 2020	Mar. 05, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Aug. 18, 2020	Jul. 09, 2020	Jun. 30, 2020	Mar. 23, 2020	Mar. 04, 2020
Notes And Loans Payable [Roll Forward]
Balance at December 31, 2019									$ 4,096,470,000
Issuances/Borrowings									1,324,360,000	$ 638,686,000
Issuances									22,750,000	0
Repayments on mortgages, notes and loans payable							$ (807,900,000)		(861,975,000)	(196,081,000)
Special Improvement District bond assumptions									(3,090,000)	(88,000)
Deferred financing costs, net									7,887,000
Balance at September 30, 2020	$ 4,219,334,000						4,219,334,000		4,219,334,000
Loss on extinguishment of debt							$ 13,166,000	$ 0	$ 13,166,000	$ 0
One-month LIBOR
Notes And Loans Payable [Roll Forward]
Interest rate margin (as a percent)									0.15%
Three-month LIBOR
Notes And Loans Payable [Roll Forward]
Interest rate margin (as a percent)									0.23%
Prime rate
Notes And Loans Payable [Roll Forward]
Interest rate margin (as a percent)									3.25%
9950 Woodloch Forest Drive
Debt Instrument [Line Items]
Interest rate (as a percent)	2.10%						2.10%		2.10%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings									$ 63,500,000
A'eo Retail
Debt Instrument [Line Items]
Interest rate (as a percent)	2.80%						2.80%		2.80%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings									$ 30,640,000
Ke Kilohana Retail
Debt Instrument [Line Items]
Interest rate (as a percent)	2.80%						2.80%		2.80%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings									$ 9,360,000
The Woodlands Towers at the Waterway
Debt Instrument [Line Items]
Interest rate (as a percent)	2.50%						2.50%		2.50%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (63,500,000)
Three Hughes Landing
Debt Instrument [Line Items]
Interest rate (as a percent)	4.33%						4.33%		4.33%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (60,766,000)
Face amount						$ 61,000,000.0									$ 61,200,000
Term of extension option						12 months
Three Hughes Landing | LIBOR
Notes And Loans Payable [Roll Forward]
Interest rate margin (as a percent)						2.60%
Two Merriweather
Debt Instrument [Line Items]
Interest rate (as a percent)	4.23%						4.23%		4.23%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (30,557,000)
100 Fellowship Drive
Debt Instrument [Line Items]
Interest rate (as a percent)	3.23%						3.23%		3.23%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable					$ (50,000,000.0)				$ (49,978,000)
HHC 242 Self-Storage
Debt Instrument [Line Items]
Interest rate (as a percent)	4.33%						4.33%		4.33%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (5,499,000)
HHC 2978 Self-Storage
Debt Instrument [Line Items]
Interest rate (as a percent)	4.33%						4.33%		4.33%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (5,395,000)
Downtown Summerlin
Debt Instrument [Line Items]
Interest rate (as a percent)	3.88%						3.88%		3.88%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable		$ (33,800,000)							$ (255,297,000)
Face amount		$ 221,500,000
Term of extension option		3 years
Downtown Summerlin | LIBOR
Notes And Loans Payable [Roll Forward]
Interest rate margin (as a percent)		2.15%
Lakefront North
Debt Instrument [Line Items]
Interest rate (as a percent)	3.73%						3.73%		3.73%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (40,062,000)
Seaport District
Debt Instrument [Line Items]
Interest rate (as a percent)	6.10%						6.10%		6.10%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (250,000,000)
Two Summerlin
Debt Instrument [Line Items]
Interest rate (as a percent)	4.25%						4.25%		4.25%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (32,803,000)
110 North Wacker
Debt Instrument [Line Items]
Interest rate (as a percent)	4.73%						4.73%		4.73%
Ae'o Retail and Ke Kilohana Retail
Notes And Loans Payable [Roll Forward]
Face amount	$ 40,000,000.0						$ 40,000,000.0		$ 40,000,000.0
Ae'o Retail and Ke Kilohana Retail | LIBOR
Notes And Loans Payable [Roll Forward]
Variable rate floor	0.25%
Interest rate margin (as a percent)	2.65%
Bridge Loan | 9950 Woodloch Forest Drive | LIBOR
Notes And Loans Payable [Roll Forward]
Interest rate margin (as a percent)				1.95%
Bridge Loan | The Woodlands Towers at the Waterway
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable				$ (63,500,000)
Bridge Loan | The Woodlands Towers at the Waterway and The Woodlands Warehouse
Notes And Loans Payable [Roll Forward]
Face amount			$ 280,300,000	$ 137,000,000.0
Term of extension option			6 months
Bridge Loan | The Woodlands Towers at the Waterway and The Woodlands Warehouse | LIBOR
Notes And Loans Payable [Roll Forward]
Interest rate margin (as a percent)			2.35%
Variable Interest Entity, Primary Beneficiary | 110 North Wacker
Notes And Loans Payable [Roll Forward]
Deconsolidation of 110 North Wacker									(326,835,000)
Existing mortgages, notes and loans payable
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings									476,604,000
Repayments on mortgages, notes and loans payable									$ (14,095,000)
Bridgeland Credit Facility
Debt Instrument [Line Items]
Interest rate (as a percent)	4.23%						4.23%		4.23%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (50,000,000)
The Woodlands Master Credit Facility
Debt Instrument [Line Items]
Interest rate (as a percent)	4.23%						4.23%		4.23%
Notes And Loans Payable [Roll Forward]
Repayments on mortgages, notes and loans payable									$ (50,000,000)
Unsecured debt | Senior Notes due 2028
Debt Instrument [Line Items]
Interest rate (as a percent)	5.375%						5.375%		5.375%		5.375%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings									$ 750,000,000
Face amount											$ 750,000,000
Special Improvement District Bonds
Notes And Loans Payable [Roll Forward]
Special Improvement District bond assumptions									$ (3,090,000)
Special Improvement District Bonds | Minimum
Debt Instrument [Line Items]
Interest rate (as a percent)	5.00%						5.00%		5.00%
Special Improvement District Bonds | Maximum
Debt Instrument [Line Items]
Interest rate (as a percent)	6.00%						6.00%		6.00%
Special Improvement District Bonds | Special Improvement District bonds
Debt Instrument [Line Items]
Interest rate (as a percent)	6.00%						6.00%		6.00%			6.00%
Notes And Loans Payable [Roll Forward]
Issuances									$ 22,750,000
Face amount												$ 22,800,000
Line of credit | Revolver Loan | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate (as a percent)	1.80%						1.80%		1.80%
Notes And Loans Payable [Roll Forward]
Borrowings, lines of credit									$ 67,500,000
Repayments, lines of credit									(67,500,000)
Loan balance	$ 0						$ 0		$ 0				$ 61,300,000	$ 67,500,000