CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 1,855	$ 221	$ 237
Restricted cash included in Prepaid expenses, assets held-for-sale and other current assets	12		12
Total cash, cash equivalents, and restricted cash at end of the period	$ 1,867	$ 232	$ 249	$ 114