Statements of Operations of Discontinued Operations (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Revenues		$ 11.0	$ 0.7	$ 29.3
Cost of sales		6.9	0.4	18.7
Gross profit		4.1	0.3	10.6
Selling, general and administrative expenses		1.7	0.6	4.9
Amortization of intangibles		0.3		0.8
Other operating expense, net	$ 0.3		1.2
Operating profit (loss)		2.1	(0.4)	4.9
Nonoperating income	(4.9)	2.4	(43.2)	3.1
Earnings before income taxes		2.5	44.2	7.0
Income tax expense	0.7	1.0	17.7	2.4
Earnings (loss) from discontinued operations, net of income taxes	$ (0.7)	1.5	26.5	4.6
Discontinued Operations
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Other operating expense, net			0.1
Nonoperating income		$ (0.4)	$ (44.6)	$ (2.1)