Note Fair value measurement (Assets measured at fair value on nonrecurring basis) (Parenthetical) (Detail) $ in Millions	9 Months Ended
Sep. 30, 2017 USD ($)
Hurricanes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Write-down	$ 2.7

Line items represent financial 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.

No definition available.

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