Segment Information - Segments Internal Financial Reports (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021	Aug. 31, 2021
Segment Reporting Information [Line Items]
Revenue	$ 682.8	$ 295.6	$ 1,233.5	$ 698.6
Earnings (loss) from operations	25.2	(25.7)	37.0	(27.8)
Assets	3,612.7		3,612.7		$ 3,390.7
Manufacturing
Segment Reporting Information [Line Items]
Revenue	555.7	201.5	1,008.2	506.0
Maintenance Services
Segment Reporting Information [Line Items]
Revenue	86.6	71.6	159.0	137.2
Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	40.5	22.5	66.3	55.4
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Earnings (loss) from operations	(27.1)	(17.3)	(43.7)	(34.8)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue	(8.3)	(4.5)	(50.7)	(25.8)
Earnings (loss) from operations		(0.1)	(0.3)	(2.6)
Intersegment Eliminations | Manufacturing
Segment Reporting Information [Line Items]
Revenue	1.8	2.4	41.2	23.0
Earnings (loss) from operations		0.1	0.3	2.6
Intersegment Eliminations | Maintenance Services
Segment Reporting Information [Line Items]
Revenue	6.1	1.6	8.8	1.9
Intersegment Eliminations | Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	0.4	0.5	0.7	0.9
Operating Segments | Manufacturing
Segment Reporting Information [Line Items]
Revenue	557.5	203.9	1,049.4	529.0
Earnings (loss) from operations	1.8	(17.7)	14.4	(9.7)
Assets	1,698.5		1,698.5		1,493.5
Operating Segments | Maintenance Services
Segment Reporting Information [Line Items]
Revenue	92.7	73.2	167.8	139.1
Earnings (loss) from operations	2.9	2.4	1.8	2.2
Assets	272.0		272.0		260.9
Operating Segments | Leasing & Management Services
Segment Reporting Information [Line Items]
Revenue	40.9	23.0	67.0	56.3
Earnings (loss) from operations	47.6	7.0	64.8	17.1
Assets	1,038.8		1,038.8		949.4
Operating Segments | Unallocated, including cash
Segment Reporting Information [Line Items]
Assets	603.4		603.4		$ 686.9
Reconciling Items | Manufacturing
Segment Reporting Information [Line Items]
Earnings (loss) from operations	1.8	(17.8)	14.1	(12.3)
Reconciling Items | Maintenance Services
Segment Reporting Information [Line Items]
Earnings (loss) from operations	2.9	2.4	1.8	2.2
Reconciling Items | Leasing & Management Services
Segment Reporting Information [Line Items]
Earnings (loss) from operations	$ 47.6	$ 7.0	$ 64.8	$ 17.1