Segments - Reconciliation of Capital Expenditures for Reportable Segments to Consolidated Amounts (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2015
ASU No. 2015-05 [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Capital expenditures reclassified as a change in other current assets	$ 1.0	$ 7.6

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.

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