Fair Value Measurements of Assets and Liabilities - Schedule of Nonfinancial Assets Measured at Fair Value on Nonrecurring Basis (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Goodwill	$ 41.0		$ 41.0
Indefinite-lived intangible assets	24.2	21.0	24.2
Goodwill	96.0		96.0
Indefinite-lived intangible assets		2.8	11.6
Fair Value Measurements at Reporting Date Using: Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Indefinite-lived intangible assets
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Indefinite-lived intangible assets
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Goodwill	41.0		41.0
Indefinite-lived intangible assets	$ 24.2	$ 21.0	$ 24.2