Other Financial Information - Other Non-current Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Deferred Credits and Other Liabilities [Abstract]
Unrecognized tax benefits	$ 451	$ 448
Deferred revenue	109	108
Noncurrent operating lease liability	70	76
Other	54	53
Total other noncurrent liabilities	$ 684	$ 685