Employee Benefit Plans	12 Months Ended
May 31, 2016
Employee Benefit Plans [Abstract]
Employee Benefit Plans	Note M — Employee Benefit Plans 401(k) plan: The Company maintains a contributory savings plan that qualifies under section 401(k) of the Internal Revenue Code. The Paychex, Inc. 401(k) Incentive Retirement Plan (the “Plan”) allows all employees to immediately participate in the salary deferral portion of the Plan, contributing up to a maximum of 50% of their salary, subject to Internal Revenue Service limitations. Employees who have completed one year of service and a minimum of 1,000 hours worked are eligible to receive a company matching contribution, when such contribution is in effect. The Company provided matching contributions of 50% of up to 8% of eligible pay that an employee contributed to the Plan, effective for pay dates on or after November 15, 2013 and 50% of up to 6% of eligible pay that an employee contributed to the Plan between February 2012 and November 2013. Company contributions to the Plan for fiscal years 2016, 2015, and 2014 were $21.4 million, $19.6 million, and $16.4 million, respectively. The Plan is 100% participant directed. Plan participants can fully diversify their portfolios by choosing from any or all investment fund choices in the Plan. Transfers in and out of investment funds, including the Paychex, Inc. Employee Stock Ownership Plan (“ESOP”) Stock Fund, are not restricted, with the exception of certain restricted trading periods for individuals designated as insiders as specified in the Company’s Insider Trading Policy. The Company match contribution, when in effect, follows the same fund elections as the employee compensation deferrals. Deferred compensation plans: The Company offers non-qualified and unfunded deferred compensation plans to a select group of key employees, executive officers, and outside directors. Eligible employees are provided with the opportunity to defer up to 50% of their annual base salary and bonus and outside directors may defer 100% of their Board cash compensation. Gains and losses are credited based on the participant’s election of a variety of investment choices. The Company does not match any participant deferral or guarantee its return. Distributions are paid at one of the following dates selected by the participant: the participant’s termination date, the date the participant retires from any active employment, or a designated specific date. The amounts accrued under these plans were $14.9 million and $14.2 million as of May 31, 2016 and May 31, 2015, respectively, and are reflected in other long-term liabilities on the accompanying Consolidated Balance Sheets.

Note M — Employee Benefit Plans

401(k) plan: The Company maintains a contributory savings plan that qualifies under section 401(k) of the Internal Revenue Code. The Paychex, Inc. 401(k) Incentive Retirement Plan (the “Plan”) allows all employees to immediately participate in the salary deferral portion of the Plan, contributing up to a maximum of 50% of their salary, subject to Internal Revenue Service limitations. Employees who have completed one year of service and a minimum of 1,000 hours worked are eligible to receive a company matching contribution, when such contribution is in effect. The Company provided matching contributions of 50% of up to 8% of eligible pay that an employee contributed to the Plan, effective for pay dates on or after November 15, 2013 and 50% of up to 6% of eligible pay that an employee contributed to the Plan between February 2012 and November 2013. Company contributions to the Plan for fiscal years 2016, 2015, and 2014 were $21.4 million, $19.6 million, and $16.4 million, respectively.

The Plan is 100% participant directed. Plan participants can fully diversify their portfolios by choosing from any or all investment fund choices in the Plan. Transfers in and out of investment funds, including the Paychex, Inc. Employee Stock Ownership Plan (“ESOP”) Stock Fund, are not restricted, with the exception of certain restricted trading periods for individuals designated as insiders as specified in the Company’s Insider Trading Policy. The Company match contribution, when in effect, follows the same fund elections as the employee compensation deferrals.

Deferred compensation plans: The Company offers non-qualified and unfunded deferred compensation plans to a select group of key employees, executive officers, and outside directors. Eligible employees are provided with the opportunity to defer up to 50% of their annual base salary and bonus and outside directors may defer 100% of their Board cash compensation. Gains and losses are credited based on the participant’s election of a variety of investment choices. The Company does not match any participant deferral or guarantee its return. Distributions are paid at one of the following dates selected by the participant: the participant’s termination date, the date the participant retires from any active employment, or a designated specific date. The amounts accrued under these plans were $14.9 million and $14.2 million as of May 31, 2016 and May 31, 2015, respectively, and are reflected in other long-term liabilities on the accompanying Consolidated Balance Sheets.