Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018		Aug. 01, 2018	Jul. 31, 2018		Dec. 31, 2017
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 695		$ 329		$ 242			$ 166
Restricted cash	218		283		319			430
Total cash, cash equivalents and restricted cash	$ 913	[1]	$ 612	[1]	$ 561	[1]	$ 1,623	$ 596	[1]	$ 575

[1] The following table provides a reconciliation of cash, cash equivalents and restricted cash to amount reported within the consolidated balance sheets. SuccessorPredecessorDecember 31,
2020December 31,
2019December 31,
2018July 31,
2018Cash and cash equivalents$695 $329 $242 $166 Restricted cash218 283 319 430 Total cash, cash equivalents and restricted cash$913 $612 $561 $596