Composition of Certain Financial Statement Items Equity Method and Non-marketable Equity Investments (Details) - USD ($) $ in Millions |
3 Months Ended | |
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Mar. 31, 2019 |
Sep. 30, 2018 |
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| Equity Method and Non-marketable Equity Investments [Line Items] | ||
| Equity method investments | $ 354 | $ 402 |
| Non-marketable equity investments | 779 | 650 |
| Carrying value of equity method and non-marketable equity investments | $ 1,133 | $ 1,052 |
| Equity Method Investee [Member] | ||
| Equity Method and Non-marketable Equity Investments [Line Items] | ||
| Non-cash consideration received from equity method investee | 98 | |
| Other Restructuring [Member] | ||
| Equity Method and Non-marketable Equity Investments [Line Items] | ||
| Non-cash consideration received for divestiture | $ 53 |
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- Definition [Line Items] for Equity Method and Non-marketable Equity Investments [Table] No definition available.
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- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of investment in equity security without readily determinable fair value. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of investment in equity method investee and investment in and advance to affiliate. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of noncash consideration received for selling an asset or business through a noncash (or part noncash) transaction. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The noncash (or part noncash) consideration received in a transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of a transaction not resulting in cash receipts or cash payments in the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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