Long-Term Debt and Credit Facilities - Interest Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Gross interest expense	$ 1,575	$ 1,743	$ 2,093
Capitalized interest	(53)	(75)	(72)
Total interest expense	$ 1,522	$ 1,668	$ 2,021