Revenue Recognition - Schedule of Capitalized Contract Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Acquisition Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	$ 183	$ 208	$ 202	$ 222
Costs incurred	31	45	96	129
Amortization	(37)	(49)	(117)	(150)
Change in contract costs held for sale	0	3	(4)	6
End of period balance	177	207	177	207
Acquisition Costs | Held-for-sale, Not Discontinued Operations | EMEA Business
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	10		6
End of period balance	10		10
Acquisition Costs | Held-for-sale | Latin American Business and ILEC Business
Capitalized Contract Cost [Roll Forward]
Beginning of period balance		31		32
End of period balance		35		35
Fulfillment Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	186	188	192	186
Costs incurred	41	38	120	119
Amortization	(35)	(35)	(106)	(113)
Change in contract costs held for sale	0	(2)	(14)	(3)
End of period balance	192	189	192	189
Fulfillment Costs | Held-for-sale, Not Discontinued Operations | EMEA Business
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	14		0
End of period balance	$ 14		$ 14
Fulfillment Costs | Held-for-sale | Latin American Business and ILEC Business
Capitalized Contract Cost [Roll Forward]
Beginning of period balance		33		34
End of period balance		$ 28		$ 28