Goodwill and Other Intangible Assets - Components of Goodwill (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($)
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 10,675
Accumulated impairment losses, beginning balance	(492)
Goodwill, net, beginning balance	10,183
Goodwill acquired	60
Goodwill disposals	(18)
Acquisition accounting adjustment	(2)
Foreign exchange	(23)
Goodwill, gross, ending balance	10,692
Accumulated impairment losses, ending balance	(492)
Goodwill, net, ending balance	10,200
HWC [Member]
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	7,904
Accumulated impairment losses, beginning balance	(130)
Goodwill, net, beginning balance	7,774
Goodwill acquired	0
Goodwill disposals	0
Acquisition accounting adjustment	(1)
Foreign exchange	(9)
Goodwill, gross, ending balance	7,894
Accumulated impairment losses, ending balance	(130)
Goodwill, net, ending balance	7,764
R&B [Member]
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	2,771
Accumulated impairment losses, beginning balance	(362)
Goodwill, net, beginning balance	2,409
Goodwill acquired	60
Goodwill disposals	(18)
Acquisition accounting adjustment	(1)
Foreign exchange	(14)
Goodwill, gross, ending balance	2,798
Accumulated impairment losses, ending balance	(362)
Goodwill, net, ending balance	$ 2,436