Revenue Recognition - Capitalized Contract Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Acquisition Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	$ 202	$ 222
Costs incurred	36	43
Amortization	(41)	(52)
Change in contract costs held for sale	(5)	2
End of period balance	192	215
Acquisition Costs | Held-for-sale, Not Discontinued Operations | EMEA Business
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	6
End of period balance	11
Acquisition Costs | Held-for-sale | Latin American Business and ILEC Business
Capitalized Contract Cost [Roll Forward]
Beginning of period balance		34
End of period balance		32
Fulfillment Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	192	186
Costs incurred	40	40
Amortization	(35)	(39)
Change in contract costs held for sale	(15)	0
End of period balance	182	187
Fulfillment Costs | Held-for-sale, Not Discontinued Operations | EMEA Business
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	0
End of period balance	$ 15
Fulfillment Costs | Held-for-sale | Latin American Business and ILEC Business
Capitalized Contract Cost [Roll Forward]
Beginning of period balance		32
End of period balance		$ 32