Reconciliation of Income Taxes at Federal Statutory Income Tax Rate (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation Of Income Taxes [Line Items]
Income tax expense (benefit) computed at federal statutory income tax rate	$ 120.7	$ 53.9	$ (15.3)
Other income taxes, net of federal tax benefit	8.0	3.8	(1.8)
Foreign taxes at a different rate than U.S. federal statutory income tax rate	(10.2)	(7.0)	(5.3)
Tax effect on foreign dividends		12.4	10.2
Tax benefit on income attributable to domestic production activities	(5.8)	(2.2)	(2.6)
Net adjustments for uncertain tax positions	2.0	(11.0)	(9.7)
Net effect of rate changes on deferred taxes	(3.0)	(0.2)	(2.9)
Prior period items		(3.9)
Valuation allowance increase (decrease)	2.1	(8.9)	16.8
Miscellaneous other, net	0.2	(2.6)	1.6
Income tax expense (benefit) as reported	$ 114.0	$ 34.3	$ (9.0)
Effective income tax rate	33.10%	22.30%	20.60%