Other Assets - Joint Ventures (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
MUMSS
Equity Method Investments
Income (loss) from investment in MUMSS	$ 36	$ 63	$ 77	$ 92

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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