Revenue Recognition - Contract Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Acquisition Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	$ 76	$ 78
Costs incurred	15	14
Amortization	(14)	(17)
End of period balance	77	75
Fulfillment Costs (1)
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	99	122
Costs incurred	21	23
Amortization	(20)	(22)
End of period balance	100	$ 123
Fulfillment Costs (1) | Discontinued Operations, Held-for-sale
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	27
End of period balance	$ 27