Summary of Significant Accounting Policies - Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Cash and cash equivalents	$ 5,826	$ 4,183
Restricted cash and cash equivalents	1,436	1,391
Total cash, cash equivalents and restricted cash and cash equivalents in the consolidated statements of cash flows	$ 7,262	$ 5,574	$ 6,046	$ 5,661