Variable Interest Entities - Consolidated Assets and Liabilities of VIEs (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
ASSETS
Buildings and improvements	$ 11,149,249	$ 11,048,433
Development costs and construction in progress	642,879	613,182
Land	1,865,806	1,867,278
Accumulated depreciation and amortization	(2,508,986)	(2,409,135)
Net real estate	11,148,948	11,119,758
Accounts receivable, net	38,879	42,269
Cash and cash equivalents	34,007	44,226	$ 716,750	$ 80,398
Intangible assets, net	495,919	519,917
Assets held for sale and discontinued operations, net	1,374,507	2,626,306
Right-of-use asset, net	198,426	192,349
Other assets, net	650,518	665,106
Total assets	15,193,926	15,920,089
Liabilities
Mortgage debt	219,959	221,621
Intangible liabilities, net	138,617	144,199
Liabilities related to assets held for sale and discontinued operations, net	328,167	415,737
Lease liability	184,425	179,895
Accounts payable, accrued liabilities, and other liabilities	697,040	763,391
Deferred revenue	765,946	774,316
Total liabilities	7,877,244	8,575,517
Consolidated Lessees VIE
ASSETS
Buildings and improvements	2,487,025	2,988,599
Development costs and construction in progress	48,600	85,595
Land	341,842	433,574
Accumulated depreciation and amortization	(533,328)	(602,491)
Net real estate	2,344,139	2,905,277
Accounts receivable, net	5,095	12,009
Cash and cash equivalents	16,464	16,550
Restricted cash	6	7,977
Intangible assets, net	89,692	179,027
Assets held for sale and discontinued operations, net	698,318	704,966
Right-of-use asset, net	89,017	95,407
Other assets, net	61,470	59,063
Total assets	3,304,201	3,980,276
Liabilities
Mortgage debt	4,537	39,085
Intangible liabilities, net	33,714	56,467
Liabilities related to assets held for sale and discontinued operations, net	186,562	190,919
Lease liability	90,397	97,605
Accounts payable, accrued liabilities, and other liabilities	53,438	102,391
Deferred revenue	31,279	90,183
Total liabilities	399,927	576,650
Consolidated Lessees VIE | Discontinued Operations
ASSETS
Buildings and improvements	633,243	639,759
Development costs and construction in progress	103	68
Land	105,769	106,209
Accumulated depreciation and amortization	(55,021)	(57,235)
Net real estate	684,094	688,801
Accounts receivable, net	1,885	1,700
Cash and cash equivalents	6,516	6,306
Restricted cash	1,388	3,124
Right-of-use asset, net	1,387	1,391
Other assets, net	3,048	3,644
Total assets	698,318	704,966
Liabilities
Mortgage debt	171,085	176,702
Liabilities related to assets held for sale and discontinued operations, net	12,119	11,003
Lease liability	1,387	1,392
Deferred revenue	1,971	1,822
Total liabilities	$ 186,562	$ 190,919