Schedule III - Real Estate and Accumulated Depreciation-Overall Summary (Details)	Dec. 31, 2021 USD ($) Property ApartmentUnit	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Overall summary of real estate and accumulated depreciation
Investment in Real Estate, Gross	$ 28,272,906,000	$ 27,203,325,000	$ 27,533,607,000	$ 26,511,022,000
Accumulated Depreciation	$ (8,354,282,000)	$ (7,859,657,000)	$ (7,276,786,000)	$ (6,696,281,000)
Investment in Real Estate - Wholly Owned Unencumbered [Member]
Overall summary of real estate and accumulated depreciation
Properties | Property	256
Units | ApartmentUnit	67,748
Investment in Real Estate, Gross	$ 23,852,899,270
Accumulated Depreciation	(7,039,743,046)
Investment in Real Estate, Net	16,813,156,224
Encumbrances	$ 0
Investment in Real Estate - Wholly Owned Encumbered [Member]
Overall summary of real estate and accumulated depreciation
Properties | Property	38
Units | ApartmentUnit	9,113
Investment in Real Estate, Gross	$ 3,414,236,833
Accumulated Depreciation	(1,014,105,838)
Investment in Real Estate, Net	2,400,130,995
Encumbrances	$ 1,959,052,708
Wholly Owned Properties
Overall summary of real estate and accumulated depreciation
Properties | Property	294
Units | ApartmentUnit	76,861
Investment in Real Estate, Gross	$ 27,267,136,103
Accumulated Depreciation	(8,053,848,884)
Investment in Real Estate, Net	19,213,287,219
Encumbrances	$ 1,959,052,708
Investment in Real Estate - Partially Owned Unencumbered [Member]
Overall summary of real estate and accumulated depreciation
Properties | Property	13
Units | ApartmentUnit	2,646
Investment in Real Estate, Gross	$ 661,445,674
Accumulated Depreciation	(217,880,998)
Investment in Real Estate, Net	443,564,676
Encumbrances	$ 0
Investment in Real Estate - Partially Owned Encumbered [Member]
Overall summary of real estate and accumulated depreciation
Properties | Property	3
Units | ApartmentUnit	900
Investment in Real Estate, Gross	$ 344,324,608
Accumulated Depreciation	(82,552,319)
Investment in Real Estate, Net	261,772,289
Encumbrances	$ 232,148,309
NONCONTROLLING INTERESTS - PARTIALLY OWNED PROPERTIES
Overall summary of real estate and accumulated depreciation
Properties | Property	16
Units | ApartmentUnit	3,546
Investment in Real Estate, Gross	$ 1,005,770,282
Accumulated Depreciation	(300,433,317)
Investment in Real Estate, Net	705,336,965
Encumbrances	$ 232,148,309
Unencumbered Properties [Member]
Overall summary of real estate and accumulated depreciation
Properties | Property	269
Units | ApartmentUnit	70,394
Investment in Real Estate, Gross	$ 24,514,344,944
Accumulated Depreciation	(7,257,624,044)
Investment in Real Estate, Net	17,256,720,900
Encumbrances	$ 0
Encumbered Properties [Member]
Overall summary of real estate and accumulated depreciation
Properties | Property	41
Units | ApartmentUnit	10,013
Investment in Real Estate, Gross	$ 3,758,561,441
Accumulated Depreciation	(1,096,658,157)
Investment in Real Estate, Net	2,661,903,284
Encumbrances	$ 2,191,201,017
Total Consolidated Investment in Real Estate [Member]
Overall summary of real estate and accumulated depreciation
Properties | Property	310
Units | ApartmentUnit	80,407
Investment in Real Estate, Gross	$ 28,272,906,385
Accumulated Depreciation	(8,354,282,201)
Investment in Real Estate, Net	19,918,624,184
Encumbrances	$ 2,191,201,017