Other Financial Data - Schedule of Other Current Assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Other Financial Data [Abstract]
Cost to fulfill contracts with customers	$ 249	$ 339
Prepaid expenses	146	111
Taxes receivable	75	95
Assets held for sale	122	0
Other	95	79
Total	$ 687	$ 624