Business Segment Information - Segment Operating Performance (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Net sales	$ 476.5	$ 448.2	$ 1,430.6	$ 1,463.4
Cost of sales	360.7	399.6	1,124.8	1,384.7
Gross margin	115.8	48.6	305.8	78.7
Operating income (loss)	60.2	(42.5)	129.7	(134.5)
Equity in earnings of investees				(0.9)
Securities earnings	6.9	6.6	20.3	19.9
Insurance recoveries	8.8	2.2	10.0	3.8
Loss on prepayment of debt	0	(2.3)	0	(8.9)
General expenses, net	(8.8)	(10.1)	(31.0)	(41.4)
Interest expense	(13.8)	(13.7)	(42.1)	(43.8)
Income (loss) before income taxes	53.3	(59.8)	86.9	(205.7)
Chemicals
Segment Reporting Information [Line Items]
Net sales	414.8	419.1	1,278.4	1,363.8
Cost of sales	319.7	372.4	1,010.2	1,304.8
Gross margin	95.1	46.7	268.2	59.0
Operating income (loss)	49.7	(35.2)	123.6	(125.6)
Component Products
Segment Reporting Information [Line Items]
Net sales	26.5	24.2	79.1	69.7
Cost of sales	18.3	16.7	54.6	48.6
Gross margin	8.2	7.5	24.5	21.1
Operating income (loss)	3.4	3.0	10.6	7.4
Waste Management
Segment Reporting Information [Line Items]
Net sales	24.5	4.9	43.4	29.9
Cost of sales	12.8	10.5	35.4	31.3
Gross margin	11.7	(5.6)	8.0	(1.4)
Operating income (loss)	6.9	(10.3)	(6.6)	(16.3)
Real Estate Management And Development
Segment Reporting Information [Line Items]
Net sales	10.7	0	29.7	0
Cost of sales	9.9	0	24.6	0
Gross margin	0.8	0	5.1	0
Operating income (loss)	0.2	0	2.1	0
Corporate Segment
Segment Reporting Information [Line Items]
Equity in earnings of investees	$ 0	$ 0	$ 0	$ (0.8)