Segment Information - Segments Internal Financial Reports (Detail) - USD ($) $ in Millions	3 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Aug. 31, 2022
Segment Reporting Information [Line Items]
Revenue	$ 766.5	$ 550.7
Earnings (loss) from operations	(4.8)	11.8
Assets	3,817.1		$ 3,851.5
Manufacturing
Segment Reporting Information [Line Items]
Revenue	646.5	452.5
Maintenance Services
Segment Reporting Information [Line Items]
Revenue	85.5	72.4
Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	34.5	25.8
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Earnings (loss) from operations	(22.5)	(16.6)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	(53.2)	(42.4)
Earnings (loss) from operations	(4.0)	(0.3)
Intersegment Eliminations | Manufacturing
Segment Reporting Information [Line Items]
Revenue	44.5	39.4
Earnings (loss) from operations	4.0	0.3
Intersegment Eliminations | Maintenance Services
Segment Reporting Information [Line Items]
Revenue	8.5	2.7
Intersegment Eliminations | Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	0.2
Operating Segments
Segment Reporting Information [Line Items]
Earnings (loss) from operations	(4.8)
Operating Segments | Manufacturing
Segment Reporting Information [Line Items]
Revenue	691.0	491.9
Earnings (loss) from operations	0.6	12.6
Assets	1,861.7		1,853.9
Operating Segments | Maintenance Services
Segment Reporting Information [Line Items]
Revenue	94.0	75.1
Earnings (loss) from operations	5.5	1.1
Assets	294.6		284.8
Operating Segments | Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	34.7	26.1
Earnings (loss) from operations	15.6	17.2
Assets	1,378.9		1,152.2
Operating Segments | Unallocated, including cash
Segment Reporting Information [Line Items]
Assets	281.9		$ 560.6
Reconciling Items | Manufacturing
Segment Reporting Information [Line Items]
Earnings (loss) from operations	(3.4)	12.3
Reconciling Items | Maintenance Services
Segment Reporting Information [Line Items]
Earnings (loss) from operations	5.5	1.1
Reconciling Items | Leasing & Management Services
Segment Reporting Information [Line Items]
Earnings (loss) from operations	$ 15.6	$ 17.2