Discontinued Operations - Operating Results of the Discontinued Operations (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Operating costs and expenses:
Loss from discontinued operations	$ (31.4)		$ (7.2)
Benefit from income taxes of discontinued operations	(8.4)		(0.8)
Net loss from discontinued operations	(23.0)		(6.4)
Aromatics [Member] | Discontinued Operations Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	32.3		163.0
Operating costs and expenses:
Cost of sales	33.1		164.0
Selling, general and administrative expenses	4.1		5.4
Restructuring and divestiture costs			0.3
Total operating costs and expenses	37.2		169.7
Operating loss from discontinued operations	(4.9)		(6.7)
Interest expense, net	(1.1)		(1.1)
Foreign currency exchange gain (loss)	(0.3)		0.6
Net loss from the sale of business	(25.1)	$ 5.3
Loss from discontinued operations	(31.4)		(7.2)
Benefit from income taxes of discontinued operations	(8.4)		(0.8)
Net loss from discontinued operations	$ (23.0)		$ (6.4)