Investment Income, Net (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
Sep. 30, 2013 |
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| Fair Value Measurements and Investments [Abstract] | |||
| Interest and dividend income on cash and investments | $ 31 | $ 25 | $ 27 |
| Gain on other investments | 3 | 8 | 5 |
| Trading Securities, Change in Unrealized Holding Gain (Loss) | (6) | (2) | 4 |
| Investment securities, trading: | |||
| Realized gains (losses), net | 2 | 6 | 2 |
| Available-for-sale Securities, Gross Realized Gain (Loss) | 21 | 1 | (1) |
| Investment securities, available-for-sale: | |||
| Other-than-temporary Impairment Losses Realized | (5) | (3) | (15) |
| Investment income | $ 46 | $ 35 | $ 22 |
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- References No definition available.
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- Definition This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This item represents the gain (loss) realized during the period from the sale of investments accounted for under the cost method of accounting and any losses recognized thereon for impairments of other than a temporary nature. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of operating dividend and interest income, including amortization and accretion of premiums and discounts, on securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition This item represents the gain realized during the period from the sale of trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of unrealized holding gain (loss) recognized in the income statement for investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Disclosure - Fair Value Measurements and Investments [Abstract] No definition available.
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- Definition Other-than-temporary impairment losses realized No definition available.
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