Funds Held for Clients and Corporate Investments (Classification of Investments on Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Aug. 31, 2023	May 31, 2023
Funds Held for Clients and Corporate Investments [Abstract]
Funds held for clients	$ 5,470.7	$ 4,118.8
Corporate investments	45.7	373.4
Long-term corporate investments	1.6	3.8
Total funds held for clients and corporate investments, Fair value	$ 5,518.0	$ 4,496.0

Funds held for clients and corporate investments.

No definition available.

Name:	payx_FundsHeldForClientsAndCorporateInvestmentsAbstract
Namespace Prefix:	payx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Funds held for clients and corporate investments, fair value.

+ References

No definition available.

+ Details

Name:	payx_FundsHeldForClientsAndCorporateInvestmentsFairValue
Namespace Prefix:	payx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481830/320-10-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(12))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479130/326-30-45-1

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of the funds held on behalf of others and that are expected to be liquidated within one year or the normal operating cycle, if longer. This does not include funds held under reinsurance agreements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(8))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_FundsHeldForClients
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in marketable security, classified as current.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_MarketableSecuritiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant