Income Taxes - Additional Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax [Line Items]
Valuation allowance	$ 8.0	$ 8.1
Deferred tax assets, valuation allowances	12.0	13.0
Undistributed earnings of foreign subsidiaries	315.4
Unrecognized tax benefits that would impact effective tax rate	3.9	5.7	8.7
Unrecognized tax benefits that would impact balance sheet tax accounts	0.1	0.2	0.4
Interest expense associated with uncertain tax positions	0.1	0.1	0.3
Accrued interest expense associated with uncertain tax positions	0.2	0.3
Reversal Of Income Tax Expense
Income Tax [Line Items]
Tax adjustments from settlement and lapse of applicable statutes of limitation	1.7		3.3
Reversal Of Pretax Interest Expense
Income Tax [Line Items]
Tax adjustments from settlement and lapse of applicable statutes of limitation	0.1		0.2
Quimica Geral Do Nordeste Sa
Income Tax [Line Items]
Deferred tax assets, valuation allowances	4.0	4.9
Foreign Tax Authority
Income Tax [Line Items]
Loss carryforward	26.7
Loss carryforward subject to expiration	$ 1.7
Loss carryforward expiration date	Dec. 31, 2018