Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	$ 136.5
Valuation Allowance, Amount	118.0
Valuation allowance other deferred tax assets	61.7
Tax loss carryforward	853.3
Operating Loss Carryforwards, Valuation Allowance	179.7
Cumulative earnings of foreign subsidiaries	1,065.8
The total gross unrecognized tax benefits	18.4
Unrecognized tax benefits, if recognized, would affect the effective income tax rate	16.9
Unrecognized tax benefits, final settlement and resolution of outstanding tax	1.4
The total amount of accrued interest and penalties	6.1	6.9
Recognized income tax expense (benefits), interest and penalties	0.9	0.9	0.6
Expire Through 2031
Income Taxes [Line Items]
Tax credit carryforwards	497.1
Without Expiry Date
Income Taxes [Line Items]
Tax credit carryforwards	$ 356.2