Segment Information - Segments Internal Financial Reports (Detail) - USD ($) $ in Millions	3 Months Ended
	Nov. 30, 2021	Nov. 30, 2020	Aug. 31, 2021
Segment Reporting Information [Line Items]
Revenue	$ 550.7	$ 403.0
Earnings (loss) from operations	11.8	(2.1)
Assets	3,470.0		$ 3,390.7
Manufacturing
Segment Reporting Information [Line Items]
Revenue	452.5	304.5
Earnings (loss) from operations	12.3	5.4
Maintenance Services
Segment Reporting Information [Line Items]
Revenue	72.4	65.6
Earnings (loss) from operations	(1.1)	(0.2)
Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	25.8	32.9
Earnings (loss) from operations	17.2	10.1
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Earnings (loss) from operations	(16.6)	(17.4)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	(42.4)	(21.3)
Earnings (loss) from operations	(0.3)	(2.5)
Intersegment Eliminations | Manufacturing
Segment Reporting Information [Line Items]
Revenue	39.4	20.6
Earnings (loss) from operations	0.3	2.5
Intersegment Eliminations | Maintenance Services
Segment Reporting Information [Line Items]
Revenue	2.7	0.3
Intersegment Eliminations | Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	0.3	0.4
Operating Segments
Segment Reporting Information [Line Items]
Earnings (loss) from operations	(16.6)	(17.4)
Operating Segments | Manufacturing
Segment Reporting Information [Line Items]
Revenue	491.9	325.1
Earnings (loss) from operations	12.6	7.9
Assets	1,550.3		1,493.5
Operating Segments | Maintenance Services
Segment Reporting Information [Line Items]
Revenue	75.1	65.9
Earnings (loss) from operations	(1.1)	(0.2)
Assets	261.5		260.9
Operating Segments | Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	26.1	33.3
Earnings (loss) from operations	17.2	$ 10.1
Assets	1,219.9		949.4
Operating Segments | Unallocated, including cash
Segment Reporting Information [Line Items]
Assets	$ 438.3		$ 686.9