Operating Segments - Narrative (Detail) $ in Millions	Sep. 30, 2015 USD ($) nonconsolidated_partner_company	Dec. 31, 2014 USD ($)
Segment Reporting Information [Line Items]
Non-consolidated partner companies \| nonconsolidated_partner_company	27
Other Items [Member]
Segment Reporting Information [Line Items]
Total assets included cash, cash equivalents, cash held in escrow, and marketable securities	$ 104.2	$ 156.5

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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