Goodwill, Customer Relationships and Other Intangible Assets - Additional Information (Details)	3 Months Ended
	Mar. 31, 2025 USD ($) reporting_unit segment	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Goodwill [Roll Forward]
Intangible assets, gross (including goodwill)	$ 15,000,000,000.0		$ 15,400,000,000
Number of reportable segments | segment	2
Goodwill	$ 1,964,000,000		1,964,000,000
Accumulated impairment losses	$ 21,700,000,000		21,700,000,000
Number of reporting units | reporting_unit	3
Goodwill impairment	$ 0
Amortization of intangible assets	252,000,000	$ 272,000,000
Business
Goodwill [Roll Forward]
Goodwill	0		0
Mass Markets
Goodwill [Roll Forward]
Goodwill	$ 2,000,000,000		$ 2,000,000,000