Fair Value Measurement - Assets Measured at Fair Value on a Nonrecurring Basis (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Long-lived assets held for sale or disposal, impairment charge			$ 11.8
Goodwill, impairment charge	$ 527.8	$ 18.0
Impairment of intangible assets		11.9
Total, impairment charge	558.3	36.5	47.3
Long-lived assets held for sale or disposal, net book value		1,852.1
Goodwill	602.0	1,085.7	1,099.2
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	5.2
Long-lived assets held for sale or disposal, impairment charge	0.6	1.5	8.7
Goodwill, impairment charge	527.8	18.0
Impairment of intangible assets	29.7	11.9	13.2
Total, impairment charge	558.1	31.7	27.1
Long-lived assets held and used, net book value			0.7
Long-lived assets held for sale or disposal, net book value			2.0
Goodwill	15.2
Other intangible assets, net book value	4.3
Total Assets	19.5		2.7
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			0.6
Long-lived assets held for sale or disposal, fair value measurement		2.8	9.2
Goodwill, fair value measurement	15.2
Other intangible assets, fair value measurement	4.6
Total, fair value measurement	$ 19.8	$ 2.8	$ 9.8