Fair Value Measurement - Narrative (Detail) (Fair Value, Measurements, Nonrecurring, USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair values reduced by estimated costs to sell	$ 0.2	$ 0.4	$ 0.8	$ 1.3