Mortgages, Notes and Loans Payable, Net (Borrowings Activity) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2021	Feb. 28, 2021
Notes And Loans Payable [Roll Forward]
Balance at December 31, 2020	$ 4,287,369
Issuances/Borrowings	1,870,378	$ 1,324,360
Repayments	(1,758,772)	(861,975)
Special Improvement District bond assumptions	(8,484)	$ (3,090)
Deferred financing costs, net	(12,282)
Balance at September 30, 2021	$ 4,423,635
Bonds
Debt Instrument [Line Items]
Interest Rate	4.00%
Notes And Loans Payable [Roll Forward]
Special Improvement District bond assumptions	$ (8,484)
Victoria Place
Debt Instrument [Line Items]
Interest Rate	5.25%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings	$ 42,718
Tanager Apartments
Debt Instrument [Line Items]
Interest Rate	3.13%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings	$ 58,500
Lakeside Row
Debt Instrument [Line Items]
Interest Rate	3.15%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings	$ 35,500
1201 Lake Robbins
Debt Instrument [Line Items]
Interest Rate	2.49%
Notes And Loans Payable [Roll Forward]
Repayments	$ (273,070)
The Woodlands Warehouse
Debt Instrument [Line Items]
Interest Rate	2.49%
Notes And Loans Payable [Roll Forward]
Repayments	$ (7,230)
Tanager Apartments
Debt Instrument [Line Items]
Interest Rate	2.50%
Notes And Loans Payable [Roll Forward]
Repayments	$ (39,992)
Lakeside Row
Debt Instrument [Line Items]
Interest Rate	2.39%
Notes And Loans Payable [Roll Forward]
Repayments	$ (31,940)
The Woodlands Resort
Debt Instrument [Line Items]
Interest Rate	3.00%
Notes And Loans Payable [Roll Forward]
Repayments	$ (62,500)
The Woodlands Master Credit Facility
Debt Instrument [Line Items]
Interest Rate	2.64%
Notes And Loans Payable [Roll Forward]
Repayments	$ (75,000)
Bridgeland Credit Facility
Debt Instrument [Line Items]
Interest Rate	2.64%
Notes And Loans Payable [Roll Forward]
Repayments	$ (75,000)
Senior Notes due 2029 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.125%		4.125%	4.125%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings	$ 650,000
Senior Notes due 2031 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	4.375%		4.375%	4.375%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings	$ 650,000
Bridgeland Notes due 2026
Debt Instrument [Line Items]
Interest Rate	2.40%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings	$ 275,000
Special Improvement District bonds | Bonds
Debt Instrument [Line Items]
Interest Rate	4.13%
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings	$ 45,425
Existing mortgages, notes and loans payable
Notes And Loans Payable [Roll Forward]
Issuances/Borrowings	158,661
Repayments	$ (12,223)
Senior Secured Credit Facility
Debt Instrument [Line Items]
Interest Rate	4.61%
Notes And Loans Payable [Roll Forward]
Repayments	$ (181,817)
Senior Notes due 2025 | Senior Notes
Debt Instrument [Line Items]
Interest Rate	5.375%		5.375%
Notes And Loans Payable [Roll Forward]
Redemption	$ (1,000,000)