Goodwill, Customer Relationships and Other Intangible Assets - Rollforward Goodwill (Details) - USD ($)					3 Months Ended	12 Months Ended
	Oct. 31, 2021	Jul. 31, 2021	Jan. 31, 2021	Oct. 31, 2020	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill Activity
As of beginning of period						$ 18,870,000,000	$ 21,534,000,000
Reclassified as held for sale						(2,859,000,000)
Effect of foreign currency exchange rate change and other						(25,000,000)	(22,000,000)
Impairment	$ 0	$ 0	$ 0	$ (2,600,000,000)	$ (6,500,000,000)	0	(2,642,000,000)	$ (6,506,000,000)
As of end of period			0			15,986,000,000	18,870,000,000	21,534,000,000
Goodwill accumulated impairment loss						7,700,000,000	12,900,000,000	10,300,000,000
Goodwill accumulated impairment loss						7,700,000,000	12,900,000,000	10,300,000,000
Disposal Group, Held-for-sale, Not Discontinued Operations
Goodwill Activity
Reclassified as held for sale						2,900,000,000
International and Global Accounts
Goodwill Activity
As of beginning of period						2,555,000,000	2,670,000,000
Effect of foreign currency exchange rate change and other							(15,000,000)
Impairment							(100,000,000)
As of end of period			(2,555,000,000)				2,555,000,000	2,670,000,000
Enterprise
Goodwill Activity
As of beginning of period						4,738,000,000	4,738,000,000
Effect of foreign currency exchange rate change and other							0
Impairment							0
As of end of period			(4,738,000,000)				4,738,000,000	4,738,000,000
Small and Medium Business
Goodwill Activity
As of beginning of period						2,808,000,000	3,259,000,000
Effect of foreign currency exchange rate change and other							(7,000,000)
Impairment							(444,000,000)
As of end of period			(2,808,000,000)				2,808,000,000	3,259,000,000
Wholesale
Goodwill Activity
As of beginning of period						3,114,000,000	3,813,000,000
Effect of foreign currency exchange rate change and other							0
Impairment							(699,000,000)
As of end of period			(3,114,000,000)				3,114,000,000	3,813,000,000
Consumer
Goodwill Activity
As of beginning of period						5,655,000,000	7,054,000,000
Effect of foreign currency exchange rate change and other							0
Impairment							(1,399,000,000)
As of end of period			(5,655,000,000)				$ 5,655,000,000	$ 7,054,000,000
Business
Goodwill Activity
Reclassified as held for sale						(913,000,000)
Effect of foreign currency exchange rate change and other						(25,000,000)
As of end of period			12,173,000,000			11,235,000,000
Mass Markets
Goodwill Activity
Reclassified as held for sale						(1,946,000,000)
Effect of foreign currency exchange rate change and other						0
As of end of period			$ 6,697,000,000			$ 4,751,000,000