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		9 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019
JPM $1 Billion Credit Facility [Member] \| JP Morgan Chase Bank, N.A. [Member]
Line of Credit Facility [Line Items]
Number of days borrowed		71 days	16 days	81 days
Maximum amount borrowed		$ 400.0	$ 694.0	$ 483.0
Weighted-average amount borrowed		$ 400.0	$ 357.1	$ 385.9
Weighted-average interest rate		3.48%	5.09%	3.66%
JPM $500 Million Credit Facility [Member] \| JP Morgan Chase Bank, N.A. [Member]
Line of Credit Facility [Line Items]
Number of days borrowed	3 days	71 days	27 days	78 days
Maximum amount borrowed	$ 273.0	$ 400.0	$ 450.0	$ 400.0
Weighted-average amount borrowed	$ 168.2	$ 400.0	$ 323.4	$ 374.1
Weighted-average interest rate	4.75%	3.48%	3.30%	3.57%
PNC $250 Million Credit Facility [Member] \| PNC Bank, National Association [Member]
Line of Credit Facility [Line Items]
Number of days borrowed	91 days		270 days
Maximum amount borrowed	$ 141.3		$ 141.3
Weighted-average amount borrowed	$ 52.3		$ 53.8
Weighted-average interest rate	2.55%		2.79%
PNC $150 Million Credit Facility [Member] \| PNC Bank, National Association [Member]
Line of Credit Facility [Line Items]
Number of days borrowed		90 days		269 days
Maximum amount borrowed		$ 58.9		$ 58.9
Weighted-average amount borrowed		$ 57.7		$ 57.0
Weighted-average interest rate		2.94%		2.72%