Summary of Significant Accounting Policies - PAC - Reconciliation of Cash (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 1,565	$ 1,591
Restricted cash included in other current assets	224	173
Restricted cash included in other assets	22	53
Total cash and cash equivalents and restricted cash and cash equivalents	1,811	1,817	$ 1,244	$ 1,445
PAC
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	138	641
Restricted cash included in other current assets	51	7
Restricted cash included in other assets	3	26
Total cash and cash equivalents and restricted cash and cash equivalents	$ 192	$ 674	$ 186	$ 19