Paychex, Inc. Quarterly report pursuant to Section 13 or 15(d)

Short-term Financing (Credit Facility Amount Borrowed) (Details) - Revolving Credit Facility [Member] - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2019	Aug. 31, 2018
JPM $1 Billion Credit Facility [Member] \| JP Morgan Chase Bank, N.A. [Member]
Line of Credit Facility [Line Items]
Number of days borrowed	6 days	6 days
Maximum amount borrowed	$ 469.0	$ 394.5
Weighted-average amount borrowed	$ 288.3	$ 216.3
Weighted-average interest rate	5.33%	4.99%
JPM $500 Million Credit Facility [Member] \| JP Morgan Chase Bank, N.A. [Member]
Line of Credit Facility [Line Items]
Number of days borrowed	10 days	4 days
Maximum amount borrowed	$ 450.0	$ 223.0
Weighted-average amount borrowed	$ 395.6	$ 133.4
Weighted-average interest rate	3.27%	4.99%
PNC $150 Million Credit Facility [Member] \| PNC Bank, National Association [Member]
Line of Credit Facility [Line Items]
Number of days borrowed	88 days	88 days
Maximum amount borrowed	$ 56.6	$ 56.8
Weighted-average amount borrowed	$ 54.8	$ 56.0
Weighted-average interest rate	3.07%	2.53%