Other Assets - Equity Method Investments - Joint Ventures (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
MUMSS
Equity Method Investments
Income (loss) from investment in MUMSS	$ 17	$ 29	$ 35	$ 113

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

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