Unaudited Interim Financial Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Quarterly Financial Data [Line Items]
Net sales	$ 867.2		$ 830.0		$ 827.1		$ 799.3		$ 791.3		$ 758.0		$ 759.9		$ 740.3		$ 3,323.6		$ 3,049.5		$ 2,958.1
Cost of goods sold	319.5		308.9		320.7		309.5		310.6		291.9		296.6		295.3		1,258.6		1,194.4		1,125.3
Income (loss) from operations before income taxes	174.7		180.3		(92.8)		183.6		1,102.7		119.0		(135.9)		127.6		445.8		1,213.4		732.4
Net income (loss)	$ 134.2		$ 131.3		$ (119.4)		$ 148.4		$ 667.5		$ 93.2		$ (161.6)		$ 90.7		$ 294.5		$ 689.8
Basic earnings (loss) per share available to common shareholders	$ 1.76	[1]	$ 1.73	[1]	$ (1.59)	[1]	$ 1.89	[1]	$ 8.45	[1]	$ 1.17	[1]	$ (2.03)	[1]	$ 1.09	[1]	$ 3.83	[1]	$ 8.54	[1]	$ 6.24
Diluted earnings (loss) per share available to common shareholders	$ 1.72	[1]	$ 1.69	[1]	$ (1.59)	[1],[2]	$ 1.86	[1]	$ 8.28	[1]	$ 1.15	[1]	$ (2.03)	[1],[2]	$ 1.08	[1]	$ 3.76	[1]	$ 8.39	[1]	$ 6.16

[1] Total per share amounts may not add due to rounding.

[2] Common share equivalents primarily from share-based compensation plans were not included in the computation of diluted weighted average shares outstanding because their effect would have been antidilutive.