Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Accounts payable and accrued liabilities	$ 83,995	$ 76,516
Operating lease liabilities	780,166	832,533
Total operating lease liabilities per the Consolidated Balance Sheet	864,161	$ 909,049
Leases not yet commenced, undiscounted lease payments	$ 29,100
Leases not yet commenced, term	13 years
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent