Fair Value Measurement - Additional Information (Detail) (Fair Value, Measurements, Nonrecurring, USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 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	$ 0.3	$ 0.9	$ 0.6	$ 0.9