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v3.24.2

Fair Value Measurements Fair Value Measurements - Investments (Details) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Jun. 30, 2024 USD ($) Units | Jun. 30, 2023 USD ($) | Jun. 30, 2024 USD ($) Units | Jun. 30, 2023 USD ($) | Sep. 30, 2023 USD ($)
Investment Gains (Losses) |  |  |  |  |
Financing Receivable, after Allowance for Credit Loss | $ 113 |  | $ 113 |  | $ 96
Period of time where the investor contributes capital to an investment in a private partnership - minimum | Units | 3 |  | 3 |  |
Period of time where the investor contributes capital to an investment in a private partnership - maximum | Units | 4 |  | 4 |  |
Minimum investment period | Units | 10 |  | 10 |  |
Number of readily available quoted exchange prices for the investments | 0 |  | 0 |  |
Investment funds | $ 4,693 |  | $ 4,693 |  | $ 4,123
NDT [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
Investment funds | 3,200 |  | 3,200 |  |
ART [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
Investment funds | 1,400 |  | 1,400 |  |
LTDCP [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
Unrealized gains (losses) on investments | 0 | $ (1) | (2) | $ (2) |
SERP |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
Unrealized gains (losses) on investments | 0 | (2) | (9) | (9) |
ART [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
Unrealized gains (losses) on investments | 4 | (24) | (119) | (145) |
Debt and Equity Securities, Unrealized Gain (Loss) | 1 | 7 | 24 | 23 |
NDT [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
Unrealized gains (losses) on investments | 21 | (51) | 230 | (292) |
Debt and Equity Securities, Unrealized Gain (Loss) | 7 | $ 31 | 70 | $ 79 |
Real Estate Funds | NDT [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
NDT unfunded commitments related to private equity and real estate | 108 |  | 108 |  |
Real Estate Funds | ART [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
NDT unfunded commitments related to private equity and real estate | 54 |  | 54 |  |
Private Equity Funds [Member] | NDT [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
NDT unfunded commitments related to private equity and real estate | 365 |  | 365 |  |
Private Equity Funds [Member] | ART [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
NDT unfunded commitments related to private equity and real estate | 139 |  | 139 |  |
Private Credit [Member] | NDT [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
NDT unfunded commitments related to private equity and real estate | 93 |  | 93 |  |
Private Credit [Member] | ART [Member] |  |  |  |  |
Investment Gains (Losses) |  |  |  |  |
NDT unfunded commitments related to private equity and real estate | $ 49 |  | $ 49 |  |

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