Property and Equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 16,239	$ 15,150	$ 12,138
Amortization of capital lease assets			$ 7,300
Amortization of lease assets	$ 8,452	$ 10,094