Other Financial Data - Summary of Components of Other Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Other Financial Data [Abstract]
Deferred revenue	$ 54	$ 60
Operating lease liabilities	132	155
Finance lease liabilities	40	59
Unrecognized tax positions	49	48
Other	83	125
Total	$ 358	$ 447