Variable Interest Entities - Consolidated Assets and Liabilities of VIEs (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
ASSETS
Buildings and improvements	$ 11,543,657	$ 11,048,433
Development costs and construction in progress	711,772	613,182
Land	1,966,665	1,867,278
Accumulated depreciation and amortization	(2,618,101)	(2,409,135)
Net real estate	11,603,993	11,119,758
Accounts receivable, net	41,814	42,269
Cash and cash equivalents	96,923	44,226	$ 672,078	$ 80,398
Intangible assets, net	511,612	519,917
Assets held for sale and discontinued operations, net	246,807	2,626,306
Right-of-use asset, net	215,303	192,349
Other assets, net	624,669	665,106
Total assets	14,332,370	15,920,089
Liabilities
Mortgage debt	358,101	221,621
Intangible liabilities, net	139,116	144,199
Liabilities related to assets held for sale and discontinued operations, net	65,272	415,737
Lease liability	189,732	179,895
Accounts payable, accrued liabilities, and other liabilities	688,458	763,391
Deferred revenue	777,687	774,316
Total liabilities	6,898,641	8,575,517
Consolidated Lessees VIE
ASSETS
Buildings and improvements	2,337,717	2,988,599
Development costs and construction in progress	46,634	85,595
Land	379,376	433,574
Accumulated depreciation and amortization	(520,226)	(602,491)
Net real estate	2,243,501	2,905,277
Accounts receivable, net	6,781	12,009
Cash and cash equivalents	26,970	16,550
Restricted cash	86,642	7,977
Intangible assets, net	102,428	179,027
Assets held for sale and discontinued operations, net	25,411	704,966
Right-of-use asset, net	108,088	95,407
Other assets, net	61,457	59,063
Total assets	2,661,278	3,980,276
Liabilities
Mortgage debt	144,263	39,085
Intangible liabilities, net	20,378	56,467
Liabilities related to assets held for sale and discontinued operations, net	4,560	190,919
Lease liability	97,849	97,605
Accounts payable, accrued liabilities, and other liabilities	52,757	102,391
Deferred revenue	34,427	90,183
Total liabilities	354,234	576,650
Consolidated Lessees VIE | Discontinued Operations
ASSETS
Buildings and improvements	32,173	639,759
Development costs and construction in progress	91	68
Land	2,724	106,209
Accumulated depreciation and amortization	(16,096)	(57,235)
Net real estate	18,892	688,801
Accounts receivable, net	2,368	1,700
Cash and cash equivalents	1,016	6,306
Restricted cash	294	3,124
Right-of-use asset, net	405	1,391
Other assets, net	2,436	3,644
Total assets	25,411	704,966
Liabilities
Mortgage debt	0	176,702
Liabilities related to assets held for sale and discontinued operations, net	3,743	11,003
Lease liability	644	1,392
Deferred revenue	173	1,822
Total liabilities	$ 4,560	$ 190,919