Derivative Instruments - Effect of Derivative Instruments on Statements of Income (Detail) - Cash Flow Hedging - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2023	Aug. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivatives	$ 32.4	$ 21.9
Gain (loss) reclassified from accumulated OCI into income	12.8	(6.1)
Gain (loss) recognized on derivative (amount excluded from effectiveness testing)	$ 2.6	1.6
Foreign Exchange Forward
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in income on derivatives		$ (0.3)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest And Foreign Exchange Net	Interest And Foreign Exchange Net
Foreign Exchange Forward | Sales
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivatives	$ 5.6	$ (4.7)
Gain (loss) reclassified from accumulated OCI into income	(0.2)	(1.5)
Gain (loss) recognized on derivative (amount excluded from effectiveness testing)	$ 2.0	$ 0.9
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax
Foreign Exchange Forward | Cost Of Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivatives	$ 2.0	$ 0.5
Gain (loss) reclassified from accumulated OCI into income	2.2	0.3
Gain (loss) recognized on derivative (amount excluded from effectiveness testing)	$ 0.6	$ 0.7
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of Revenue	Cost of Revenue
Interest rate swap contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivatives	$ 24.8	$ 26.1
Gain (loss) reclassified from accumulated OCI into income	$ 10.8	$ (4.9)
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest And Foreign Exchange Net	Interest And Foreign Exchange Net