Income Taxes - Components of Comprehensive Provision for Income Taxes Allocation (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Income Tax [Line Items]
United States	$ 89.0	$ 51.6	$ (0.8)
Non-U.S. subsidiaries	212.4	409.2	79.6
Income from continuing operations before income taxes	301.4	460.8	78.8
Expected tax expense, at U.S. federal statutory income tax rate of 35%	105.4	161.3	27.6
Non-U.S. tax rates	(11.9)	(17.1)	(3.8)
Incremental U.S. tax on earnings of non-U.S. companies	1.0	28.8	18.3
German tax attribute adjustments			(35.2)
U.S. state income taxes, net	1.3	4.0	3.1
Adjustment to the reserve for uncertain tax positions, net	4.2	(8.5)	5.2
Change in valuation allowance	(1.1)	(0.7)	(0.1)
Nondeductible expenses	4.3	3.7	2.5
Tax rate changes	1.9	(0.1)	(1.5)
French dividend surtax	0.3
Other, net	(0.6)	(1.5)	(1.6)
Provision for income taxes	104.8	169.9	14.5
Income from continuing operations	104.8	169.9	14.5
Income from discontinued operations	5.4	5.0	4.0
Other comprehensive income:
Marketable securities	(11.6)	7.7	6.0
Currency translation	4.9		(0.2)
Total	84.5	175.1	25.9
Defined Benefit Pension Plans [Member]
Other comprehensive income:
Defined benefit plans	(18.3)	(6.5)	(0.5)
OPEB [Member]
Other comprehensive income:
Defined benefit plans	$ (0.7)	$ (1.0)	$ 2.1