Investments - Additional Information (Detail) - USD ($) $ in Millions |
Jun. 30, 2018 |
Jun. 30, 2017 |
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| U.S. Government and Agency Securities | ||
| Investment [Line Items] | ||
| Collateral received | $ 1,800 | $ 3,700 |
| Fair Value, Measurements, Nonrecurring | ||
| Investment [Line Items] | ||
| Recorded basis of common and preferred stock that are restricted for more than one year or are not publicly traded | $ 999 | $ 1,073 |
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- Definition Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments. No definition available.
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- Definition The carrying value as of the balance sheet date of the assets received as collateral against securities loaned to other broker-dealers. Borrowers of securities generally are required to provide collateral to the lenders of securities, commonly cash but sometimes other securities or standby letters of credit, with a value slightly higher than that of the securities borrowed. In instances where the entity is permitted to sell or re-pledge these securities, the entity reports the fair value of the collateral received and the related obligation to return the collateral as a liability. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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