Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Reclassification of derivative financial instruments recognized in net earnings (loss), tax	$ 0.6	$ 0.1	$ 0.8	$ 0.5
Unrealized loss on derivative financial instruments, tax	$ 2.1	$ 0.5	$ 2.8	$ 1.6

Amount of tax expense (benefit) for reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e640-108580

Name:	us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration