Fair Value Measurement - Schedule of Assets Measured at Fair Value on a Nonrecurring Basis (Detail) (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 Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total, impairment charge			$ 10.1	$ 16.6
Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-lived assets held and used, impairment charge	0	3.2	1.9	4.4
Long-lived assets held for sale or disposal, impairment charge	2.1	5.4	9.3	12.6
Other intangible assets, impairment charge	0		1.0
Total, impairment charge	2.1	8.6	12.2	17.0
Long-lived assets held and used, net book value	1.2	4.4	1.2	4.4
Long-lived assets held for sale or disposal, net book value	5.4	17.1	5.4	17.1
Other intangible assets, net book value	0		0
Total, net book value	6.6	21.5	6.6	21.5
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-lived assets held and used, fair value measurement	0	3.7	1.4	4.6
Long-lived assets held for sale or disposal, fair value measurement	2.3	5.2	13.7	18.8
Other intangible assets, fair value measurement	0		0
Total, fair value measurement	$ 2.3	$ 8.9	$ 15.1	$ 23.4