Segment Reporting - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting
Total revenue	$ 644,559	$ 561,743	$ 1,258,486	$ 1,112,879
NOI	444,287	359,770	859,011	711,336
Gross real estate	25,234,333	23,652,841	25,234,333	23,652,841
Gross real estate assets held for sale	152,391		152,391
Operating Segments | Same Store
Segment Reporting
Total revenue	568,176	502,211	1,109,423	1,000,161
NOI	396,846	338,642	769,706	675,765
Gross real estate	20,355,305	20,162,672	20,355,305	20,162,672
Operating Segments | Same Store | New England
Segment Reporting
Total revenue	85,966	76,028	167,783	150,899
NOI	57,413	49,292	110,000	96,738
Gross real estate	2,897,758	2,866,866	2,897,758	2,866,866
Operating Segments | Same Store | Metro NY/NJ
Segment Reporting
Total revenue	114,791	101,709	224,674	203,312
NOI	80,041	68,865	155,980	138,806
Gross real estate	4,099,129	4,064,542	4,099,129	4,064,542
Operating Segments | Same Store | Mid-Atlantic
Segment Reporting
Total revenue	85,191	79,090	167,284	157,194
NOI	57,944	52,583	113,936	105,634
Gross real estate	3,264,662	3,237,943	3,264,662	3,237,943
Operating Segments | Same Store | Southeast Florida
Segment Reporting
Total revenue	9,439	7,706	18,510	14,948
NOI	6,171	4,557	12,148	8,746
Gross real estate	397,445	395,009	397,445	395,009
Operating Segments | Same Store | Denver, CO
Segment Reporting
Total revenue	6,663	5,853	12,978	11,505
NOI	4,900	3,935	9,627	7,954
Gross real estate	321,043	319,994	321,043	319,994
Operating Segments | Same Store | Pacific Northwest
Segment Reporting
Total revenue	36,310	31,035	70,608	61,567
NOI	26,101	21,024	50,323	41,414
Gross real estate	1,292,648	1,284,135	1,292,648	1,284,135
Operating Segments | Same Store | Northern California
Segment Reporting
Total revenue	100,487	92,080	197,216	184,935
NOI	72,072	65,022	140,771	130,574
Gross real estate	3,661,197	3,620,936	3,661,197	3,620,936
Operating Segments | Same Store | Southern California
Segment Reporting
Total revenue	129,329	108,710	250,370	215,801
NOI	92,204	73,364	176,921	145,899
Gross real estate	4,421,423	4,373,247	4,421,423	4,373,247
Operating Segments | Other Stabilized
Segment Reporting
Total revenue	48,708	26,886	94,308	47,844
NOI	33,269	16,326	62,811	27,298
Gross real estate	2,583,348	1,806,053	2,583,348	1,806,053
Operating Segments | Development / Redevelopment
Segment Reporting
Total revenue	21,072	8,951	38,589	16,024
NOI	14,172	4,802	26,494	8,273
Gross real estate	1,910,921	1,261,434	1,910,921	1,261,434
Operating Segments | Disposals
Segment Reporting
Gross real estate		398,960		398,960
Land Held for Future Development
Segment Reporting
Gross real estate	194,458	100,106	194,458	100,106
Non-allocated
Segment Reporting
Total revenue	904	808	1,656	1,685
Gross real estate	190,301	322,576	190,301	322,576
Continuing Operations
Segment Reporting
Total revenue	638,860	538,856	1,243,976	1,065,714
Continuing Operations | Operating Segments | Same Store
Segment Reporting
Total revenue	568,176	502,211	1,109,423	1,000,161
Continuing Operations | Operating Segments | Other Stabilized
Segment Reporting
Total revenue	48,708	26,886	94,308	47,844
Continuing Operations | Non-allocated
Segment Reporting
Total revenue	$ 904	$ 808	$ 1,656	$ 1,685