Service Revenue (Summary of Changes in Deferred Costs to Obtain and Fulfill Contracts) (Details) $ in Millions	3 Months Ended
Aug. 31, 2018 USD ($)
Costs To Obtain A Contract [Member]
Capitalized Contract Cost [Line Items]
Beginning balance	$ 455.0
Capitalization of costs	32.4
Amortization	(38.9)
Ending balance	448.5
Costs To Fulfill A Contract [Member]
Capitalized Contract Cost [Line Items]
Beginning balance	65.4
Capitalization of costs	6.0
Amortization	(5.7)
Ending balance	$ 65.7

Capitalized Contract Cost

No definition available.

Name:	payx_CapitalizedContractCost
Namespace Prefix:	payx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of amortization expense for asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

+ Details

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Balance Type:	debit
Period Type:	instant

- Details

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Balance Type:
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- Details

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