Paychex, Inc. Annual report pursuant to Section 13 and 15(d)

Short-term Financing (Credit Facility Amount Borrowed) (Details) - Revolving Credit Facility [Member] - USD ($) $ in Millions	12 Months Ended
	May 31, 2019	May 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	95 days	22 days
Maximum amount borrowed	$ 483.0	$ 700.0
Weighted-average amount borrowed	$ 387.7	$ 319.1
Weighted-average interest rate	3.64%	4.27%
JPM $500 Million Credit Facility [Member] \| JP Morgan Chase Bank, N.A. [Member]
Line of Credit Facility [Line Items]
Number of days borrowed	92 days	42 days
Maximum amount borrowed	$ 400.0	$ 400.0
Weighted-average amount borrowed	$ 375.6	$ 144.8
Weighted-average interest rate	3.55%	2.80%
PNC $150 Million Credit Facility [Member] \| PNC Bank, National Association [Member]
Line of Credit Facility [Line Items]
Number of days borrowed	359 days	358 days
Maximum amount borrowed	$ 58.9	$ 59.9
Weighted-average amount borrowed	$ 56.1	$ 57.2
Weighted-average interest rate	2.81%	1.94%