Income Taxes - Components of Comprehensive Provision for Income Taxes Allocation (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Schedule Of Income Tax [Line Items]
Expected tax expense (benefit), at U.S. federal statutory income tax rate of 35%	$ (10.1)	$ 8.9	$ (2.5)	$ 11.8
Incremental net benefit on earnings and losses of non-U.S. and non-tax group companies	(28.6)	(1.1)	(28.1)	(1.2)
Non-U.S. tax rates	0.5	(1.0)	(0.6)	(1.7)
Valuation allowance	150.3		150.3
Adjustment to the reserve for uncertain tax positions, net	(0.2)	(5.9)	(2.9)	(5.6)
Nondeductible expenses	(0.6)	0.9	(0.1)	1.2
Domestic manufacturing credit	(0.2)	(0.6)	(1.0)	(0.7)
U.S. state income taxes and other, net	(0.5)	0.3	(0.2)	1.5
Income tax expense	110.6	1.5	114.9	5.3
Comprehensive provision for income taxes (benefit) allocable to:
Income tax expense	110.6	1.5	114.9	5.3
Other comprehensive income (loss):
Marketable securities	(0.5)	(2.4)	(0.7)	(11.2)
Currency translation	8.1	(0.9)	(8.1)	(1.6)
Total	118.2	(1.1)	107.2	(6.0)
Defined Benefit Pension Plans
Other comprehensive income (loss):
Defined benefit plans	0.2	0.9	1.5	1.9
OPEB
Other comprehensive income (loss):
Defined benefit plans	$ (0.2)	$ (0.2)	$ (0.4)	$ (0.4)