Business Segment Information - Segment Operating Performance (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
Segment Reporting Information [Line Items]
Net sales	$ 491.7	$ 516.0	$ 954.1	$ 1,015.2
Cost of sales	387.5	498.8	764.1	985.1
Gross margin	104.2	17.2	190.0	30.1
Operating income (loss)	46.7	(46.8)	69.5	(92.0)
Equity in earnings of investees				(0.8)
Securities earnings	6.6	6.7	13.4	13.3
Insurance recoveries	0.4	1.0	1.2	1.6
Loss on prepayment of debt				(6.6)
General expenses, net	(13.9)	(21.6)	(22.2)	(31.3)
Interest expense	(14.6)	(14.7)	(28.3)	(30.1)
Income (loss) before income taxes	25.2	(75.9)	33.6	(145.9)
Chemicals
Segment Reporting Information [Line Items]
Net sales	443.5	481.1	863.6	944.7
Cost of sales	350.3	472.1	690.5	932.4
Gross margin	93.2	9.0	173.1	12.3
Operating income (loss)	46.3	(45.3)	73.9	(90.4)
Component products
Segment Reporting Information [Line Items]
Net sales	26.8	24.0	52.6	45.5
Cost of sales	18.3	16.4	36.3	31.9
Gross margin	8.5	7.6	16.3	13.6
Operating income (loss)	3.9	2.9	7.2	4.4
Waste management
Segment Reporting Information [Line Items]
Net sales	11.9	10.9	18.9	25.0
Cost of sales	11.9	10.3	22.6	20.8
Gross margin		0.6	(3.7)	4.2
Operating income (loss)	(5.0)	(4.4)	(13.5)	(6.0)
Real Estate Management And Development
Segment Reporting Information [Line Items]
Net sales	9.5		19.0
Cost of sales	7.0		14.7
Gross margin	2.5		4.3
Operating income (loss)	1.5		1.9
Corporate segment
Segment Reporting Information [Line Items]
Equity in earnings of investees		$ (0.5)		$ (0.8)