Changes in Self Insurance Reserves (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Disclosure Changes in Self Insurance Reserves [Abstract]
Beginning Balance	$ 21.5	$ 27.6
Accruals (reversals), net	13.8	5.8
Payments	(11.5)	(11.9)
Ending Balance	$ 23.8	$ 21.5

Carrying amount of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property that are expected to be paid within one year (or the normal operating cycle, if longer).

No definition available.

Name:	us-gaap_SelfInsuranceReserveCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant