Revenue Recognition - Capitalized Contract Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2022
Acquisition Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	$ 185	$ 183	$ 202	$ 182	$ 202
Costs incurred	36	31		104	96
Amortization	(32)	(37)		(97)	(117)
Change in contract costs held for sale				0	(4)
End of period balance	189	177	183	189	177	$ 202
Acquisition Costs | Held-for-sale | EMEA Business
Capitalized Contract Cost [Roll Forward]
Classified as held for sale		10	10		10	6
Fulfillment Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	204	186	192	184	192
Costs incurred	41	41		126	120
Amortization	(36)	(35)		(101)	(106)
Change in contract costs held for sale				0	(14)
End of period balance	$ 209	192	186	$ 209	192	192
Fulfillment Costs | Held-for-sale | EMEA Business
Capitalized Contract Cost [Roll Forward]
Classified as held for sale		$ 14	$ 14		$ 14	$ 0