SCHEDULE III (Details2) - USD ($)		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022	Dec. 31, 2021
Noncontrolling Interest in Joint Ventures		$ 774,000		$ 700,000	$ 1,379,000
Estimated aggregate cost of real estate properties for federal income tax purposes		5,124,320,000
Estimated accumulated tax depreciation		959,555,000
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at beginning of year	[1]	4,934,421,000		4,051,325,000	3,519,085,000
Purchases of real estate properties		160,105,000		353,221,000	104,205,000
Development of real estate properties and value-add properties		388,213,000		506,154,000	415,260,000
Improvements to real estate properties		51,643,000		40,654,000	36,692,000
Right-of-use asset, net - ground leases		(1,395,000)		(3,244,000)	11,562,000
Real estate assets held for sale		0		0	(18,233,000)
Carrying amount of investments sold		(33,022,000)		(9,811,000)	(15,288,000)
Write-off of improvements		(6,770,000)		(3,878,000)	(1,958,000)
Balance at end of year	[1]	5,493,195,000	[2],[3]	4,934,421,000	4,051,325,000
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at beginning of year		1,150,814,000		1,035,617,000	955,328,000
Depreciation expense		141,003,000		125,199,000	104,910,000
Real estate assets held for sale		0		0	(12,538,000)
Accumulated depreciation on assets sold		(11,759,000)		(6,068,000)	(10,178,000)
Other		(6,335,000)		(3,934,000)	(1,905,000)
Balance at end of year		$ 1,273,723,000	[2],[3]	$ 1,150,814,000	$ 1,035,617,000
Buildings [Member]
Property, Plant and Equipment, Useful Life		40 years
Minimum [Member] | Building Improvements
Property, Plant and Equipment, Useful Life		3 years
Maximum [Member] | Building Improvements
Property, Plant and Equipment, Useful Life		15 years

[1] Includes noncontrolling interest in joint ventures of $774,000, $700,000 and $1,379,000 at December 31, 2023, 2022 and 2021, respectively.

[2] The estimated aggregate cost of real estate properties at December 31, 2023 for federal income tax purposes was approximately $5,124,320,000 before estimated accumulated tax depreciation of $959,555,000.  The federal income tax return for the year ended December 31, 2023, has not been filed and accordingly, this estimate is based on preliminary data.

[3] Changes in Real Estate Properties and Development and Value-Add Properties follow:                                                                                                                                                                                                                                                                                                                                                                                    Years Ended December 31,202320222021(In thousands)Balance at beginning of year $4,934,421 4,051,325 3,519,085 Purchases of real estate properties 160,105 353,221 104,205 Development of real estate properties and value-add properties388,213 506,154 415,260 Improvements to real estate properties51,643 40,654 36,692 Right-of-use assets, net – ground leases(1,395)(3,244)11,562 Real estate assets held for sale— — (18,233)Carrying amount of investments sold (33,022)(9,811)(15,288)Write-off of improvements (6,770)(3,878)(1,958) Balance at end of year (1)  $5,493,195 4,934,421 4,051,325 
(1) Includes noncontrolling interest in joint ventures of $774,000, $700,000 and $1,379,000 at December 31, 2023, 2022 and 2021, respectively.
Changes in the accumulated depreciation on real estate properties follow:                                                                                                                                                                                                                                                                                                                                                                                   Years Ended December 31,202320222021(In thousands)Balance at beginning of year $1,150,814 1,035,617 955,328 Depreciation expense 141,003 125,199 104,910 Real estate assets held for sale— — (12,538)Accumulated depreciation on assets sold (11,759)(6,068)(10,178)Other (6,335)(3,934)(1,905)Balance at end of year $1,273,723 1,150,814 1,035,617