Fair Value Measurement - Assets Measured at Fair Value on a Nonrecurring Basis (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Goodwill, impairment charge	$ 18.1		$ 18.1
Impairment of intangible assets		158.0
Total, impairment charge			47.3	21.5	1,027.1
Goodwill	1,706.6	1,436.4	1,706.6	1,436.3	1,436.4
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			5.4	4.2	8.0
Long-lived assets held for sale or disposal, impairment charge			12.5	14.8	15.6
Goodwill, impairment charge			18.1		848.4
Impairment of intangible assets			15.0	3.3	158.0
Total, impairment charge			51.0	22.3	1,030.0
Long-lived assets held and used, net book value	1.3	8.5	1.3	4.0	8.5
Long-lived assets held for sale or disposal, net book value	3.2	6.3	3.2	18.5	6.3
Goodwill	0	18.1	0		18.1
Other intangible assets, net book value	0	3.1	0	0	3.1
Total Assets	4.5	36.0	4.5	22.5	36.0
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			1.3	4.2	9.8
Long-lived assets held for sale or disposal, fair value measurement			20.8	20.2	16.4
Goodwill, fair value measurement	0	18.1	0		18.1
Other intangible assets, fair value measurement			0	0	3.1
Total, fair value measurement			$ 22.1	$ 24.4	$ 47.4