Employee Deferred Savings Plan - Company Recorded Contributions To Plan (Detail) - USD ($) $ in Millions	12 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Compensation And Retirement Disclosure [Abstract]
Deferred savings plan Company contributions	$ 8.3	$ 7.2	$ 6.6

Amount of contribution received by defined benefit plan from employer which increases plan assets.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
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Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration