Leases - Operating Lease Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Lease Expense
Long-term fixed lease	$ 255	$ 288	$ 233
Long-term variable lease	32	25	48
Short-term lease	440	477	706
Total operating lease expense	$ 727	$ 790	$ 987