Variable Interest Entities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Assets:
Net real estate investments	$ 30,950,061			$ 28,474,947
Cash and cash equivalents	303,982			1,545,046
Receivables and other assets	774,884			629,031
Total Assets	33,480,025			32,483,642
Liabilities and equity:
Secured debt	2,262,345			2,377,930
Lease liabilities	544,547			418,266
Total equity	17,782,916	$ 16,850,829	$ 16,691,017	16,881,572	$ 16,961,102	$ 16,936,527	$ 17,066,337	$ 16,506,627
Total liabilities and equity	33,480,025			32,483,642
VIE, Primary Beneficiary
Assets:
Net real estate investments	451,723			454,333
Cash and cash equivalents	15,067			15,547
Receivables and other assets	7,999			11,171
Total Assets	474,789			481,051
Liabilities and equity:
Secured debt	164,010			165,671
Lease liabilities	3,648			1,325
Accrued expenses and other liabilities	12,939			14,997
Total equity	294,192			299,058
Total liabilities and equity	$ 474,789			$ 481,051