Income Taxes - Component of Income Taxes Expenses (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Tax Expenses [Line Items]
Expected tax expense (benefit), at U.S. federal statutory income tax rate of 35%	$ 8.9	$ (26.5)	$ 11.8	$ (51.0)
Incremental benefit on earnings of non-U.S. and non-tax group companies	(1.1)	(3.3)	(1.2)	(4.7)
Non-U.S. tax rates	(1.0)	2.9	(1.7)	2.5
Adjustment to the reserve for uncertain tax positions, net	(5.9)	(0.3)	(5.6)	1.7
Nondeductible expenses	0.9	0.1	1.2	2.6
U.S. state income taxes and other, net	(0.3)	(0.2)	0.8	(0.2)
Income tax expense (benefit)	1.5	(27.3)	5.3	(49.1)
Comprehensive provision for income taxes (benefit) allocable to:
Net income (loss)	1.5	(27.3)	5.3	(49.1)
Other comprehensive income (loss), net of tax:
Marketable securities	(2.4)	(2.4)	(11.2)	1.2
Currency translation	(0.9)	2.5	(1.6)	(1.3)
Total	(1.1)	(26.1)	(6.0)	(47.1)
Defined Benefit Pension Plans
Other comprehensive income (loss), net of tax:
Defined benefit plans	0.9	1.2	1.9	2.4
OPEB
Other comprehensive income (loss), net of tax:
Defined benefit plans	$ (0.2)	$ (0.1)	$ (0.4)	$ (0.3)