Acquisitions and Dispositions - Pro Forma Adjustments Affecting Net Earnings (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015
Business Combinations [Abstract]
Depreciation and amortization of purchased assets, pre-tax	$ 2.0	$ 2.4
Acquisition-related expenses, pre-tax	0.2	18.8
Restructuring, impairment and other charges, pre-tax	4.5	28.6
Inventory fair value adjustment, pre-tax	6.7	9.9
Other pro forma adjustments, pre-tax	0.0	1.2
Income taxes	$ (4.8)	$ (15.0)