Goodwill, Customer Relationships and Other Intangible Assets - Additional Information (Details)	3 Months Ended			9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) segment reporting_unit	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Goodwill [Roll Forward]
Intangible assets, gross (including goodwill)	$ 15,500,000,000			$ 15,500,000,000		$ 15,800,000,000
Number of reportable segments | segment				2
Goodwill	1,964,000,000			$ 1,964,000,000		1,964,000,000
Accumulated impairment losses	21,700,000,000			$ 21,700,000,000		21,700,000,000
Number of reporting units | reporting_unit				3
Goodwill impairment	0	$ 0	$ 8,800,000,000	$ 0	$ 8,793,000,000
Amortization of intangible assets	253,000,000	$ 271,000,000		802,000,000	$ 794,000,000
Minimum | Revenue Multiple
Goodwill [Roll Forward]
Goodwill impairment, measurement input			1.5
Minimum | EBITDA Multiple
Goodwill [Roll Forward]
Goodwill impairment, measurement input			4.6
Maximum | Revenue Multiple
Goodwill [Roll Forward]
Goodwill impairment, measurement input			4.3
Maximum | EBITDA Multiple
Goodwill [Roll Forward]
Goodwill impairment, measurement input			10.5
Business
Goodwill [Roll Forward]
Goodwill	0			0		0
Mass Markets
Goodwill [Roll Forward]
Goodwill	$ 2,000,000,000			$ 2,000,000,000		$ 2,000,000,000