Revenue Recognition - Contract Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Acquisition Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	$ 78	$ 79
Costs incurred	58	61
Amortization	(60)	(62)
Reclassified as held for sale	0
End of period balance	76	78
Fulfillment Costs
Capitalized Contract Cost [Roll Forward]
Beginning of period balance	122	121
Costs incurred	90	88
Amortization	(86)	(87)
Reclassified as held for sale	(27)
End of period balance	$ 99	$ 122