Summary of Significant Accounting Policies - Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements
Operating lease assets	$ 769,487	$ 807,537
Operating lease liabilities	866,960
Property and equipment, net	(367,898)	(314,374)
Deferred revenues and gains, current portion	(88,213)	(87,093)
Accrued liabilities	(137,688)	(130,316)
Other long-term liabilities	(54,920)	(35,467)
Retained deficit	(21,814)	(83,134)
Non-controlling interests	$ (36,005)	$ (126,634)