Segment Information - Reconciliation of Adjusted EBITDA from Segment to Consolidated Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 34,708	$ 30,826	$ 34,258
Adjustments	87	233	180
Depreciation	(8,628)	(8,320)	(8,663)
Amortization	(5,176)	(4,780)	(4,290)
Interest expense	(4,281)	(4,588)	(4,567)
Investment and other income (loss), net	2,557	1,160	438
Income before income taxes	$ 19,093	14,065	$ 16,996
Gain (loss) Related to Legal Settlement
Segment Reporting Information [Line Items]
Adjustments		$ 177