Stockholders' Equity - Total Share-based Incentive Compensation Expense (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	$ 54.1	$ 24.1	[1]	$ 16.9	[1]
Associated tax benefits recognized	15.7	7.8		6.2
2014 Special PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	11.8
2014 Three-year PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	6.8
2013 Three-year PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	8.2	4.4
2012 Three-year PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	1.8	2.4		1.9
2011 Three-year PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense		(1.2)		1.7
2010 Three-year PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense		0.1		0.9
2013 WVH Incentive Compensation [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	1.3	2.5
2012 CEO Incentive Compensation [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	0.4	0.6		0.2
SLO Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	4.6	2.8		0.7
Other long-term share based incentive compensation programs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based incentive compensation expense	$ 19.2	$ 12.5		$ 11.5

[1] Certain amounts have been revised to reflect the retrospective application of the Company’s change in inventory costing method for certain U.S. inventories to the FIFO method from the LIFO method. Refer to Note 2, “Summary of Significant Accounting Policies - Inventories,” of the notes to consolidated financial statements for further details surrounding this accounting policy change.