Variable Interest Entities - Consolidated Assets and Liabilities of VIEs (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
ASSETS
Buildings and improvements	$ 11,759,664	$ 11,048,433
Development costs and construction in progress	845,382	613,182
Land	2,206,422	1,867,278
Accumulated depreciation and amortization	(2,734,832)	(2,409,135)
Net real estate	12,076,636	11,119,758
Accounts receivable, net	44,699	42,269
Cash and cash equivalents	201,099	44,226	$ 139,797	$ 80,398
Intangible assets, net	520,335	519,917
Assets held for sale and discontinued operations, net	105,009	2,626,306
Right-of-use asset, net	218,524	192,349
Other assets, net	678,638	665,106
Total assets	14,743,502	15,920,089
Liabilities
Mortgage debt	356,570	221,621
Intangible liabilities, net	144,004	144,199
Liabilities related to assets held for sale and discontinued operations, net	18,910	415,737
Lease liability	191,444	179,895
Accounts payable, accrued liabilities, and other liabilities	729,939	760,617
Deferred revenue	782,413	774,316
Total liabilities	7,405,114	8,572,743
Consolidated Lessees VIE
ASSETS
Buildings and improvements	2,419,928	2,988,599
Development costs and construction in progress	62,400	85,595
Land	459,425	433,574
Accumulated depreciation and amortization	(541,890)	(602,491)
Net real estate	2,399,863	2,905,277
Accounts receivable, net	7,950	12,009
Cash and cash equivalents	31,670	16,550
Restricted cash	86	7,977
Intangible assets, net	117,073	179,027
Assets held for sale and discontinued operations, net	3,480	704,966
Right-of-use asset, net	107,492	95,407
Other assets, net	67,268	59,063
Total assets	2,734,882	3,980,276
Liabilities
Mortgage debt	144,333	39,085
Intangible liabilities, net	24,863	56,467
Liabilities related to assets held for sale and discontinued operations, net	3,032	190,919
Lease liability	98,042	97,605
Accounts payable, accrued liabilities, and other liabilities	58,025	102,391
Deferred revenue	33,474	90,183
Total liabilities	361,769	576,650
Consolidated Lessees VIE | Discontinued Operations
ASSETS
Buildings and improvements	0	639,759
Development costs and construction in progress	0	68
Land	0	106,209
Accumulated depreciation and amortization	0	(57,235)
Net real estate	0	688,801
Accounts receivable, net	1,298	1,700
Cash and cash equivalents	1,419	6,306
Restricted cash	0	3,124
Right-of-use asset, net	0	1,391
Other assets, net	763	3,644
Total assets	3,480	704,966
Liabilities
Mortgage debt	0	176,702
Liabilities related to assets held for sale and discontinued operations, net	3,032	11,003
Lease liability	0	1,392
Deferred revenue	0	1,822
Total liabilities	$ 3,032	$ 190,919