Discontinued Operations - Results of Discontinued Operations (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net income (loss) from discontinued operations (Note 2)	$ 0.4	$ 0.6	$ (19.5)
Logistics
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net sales	11.0		33.8
Business Services | Disposition by Sale | Logistics
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net sales	190.5		558.5
Cost of sales	(164.1)		(484.1)
Selling, general, administrative and other operating expenses	(21.3)		(69.7)
Restructuring, impairment and other expense	(0.2)		(21.0)
Operating income (loss) from discontinued operations	4.9		(16.3)
Income tax expense	(4.5)		(3.2)
Net income (loss) from discontinued operations (Note 2)	$ 0.4		$ (19.5)