Revenue Recognition - Capitalized Contract Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Acquisition Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	$ 222	$ 289
Costs incurred	43	44
Amortization	(52)	(54)
Change in contract costs held for sale	2	0
End of period balance	215	279
Acquisition Costs | Held-for-sale
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	32
End of period balance	34
Fulfillment Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	186	216
Costs incurred	40	37
Amortization	(39)	(37)
Change in contract costs held for sale	0	0
End of period balance	187	$ 216
Fulfillment Costs | Held-for-sale
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	32
End of period balance	$ 32