Leases - Lease Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Leases [Abstract]
Finance Lease, Right-of-Use Asset	$ 60,800		$ 60,800		$ 57,400
Operating lease cost	1,149	$ 874	2,217	$ 1,710
Finance lease amortization of lease assets	2,029	2,402	3,923	4,709
Finance lease interest on lease liabilities	156	160	320	316
Finance lease cost	2,185	2,562	4,243	5,025
Variable lease cost	294	281	558	531
Total lease cost	$ 3,628	$ 3,717	$ 7,018	$ 7,266