Description of Business, Basis of Presentation, and Significant Accounting Policies (Policies)	3 Months Ended
Aug. 31, 2012
Description of Business, Basis of presentation, and Significant Accounting Policies [Abstract]
Description of business	*Description of business:* Paychex, Inc. and its wholly owned subsidiaries (collectively, the “Company” or “Paychex”) is a leading provider of payroll, human resource, and benefits outsourcing solutions for small- to medium-sized businesses in the United States (“U.S.”). The Company also has a subsidiary in Germany. Paychex, a Delaware corporation formed in 1979, reports as one segment. Substantially all of the Company’s revenue is generated within the U.S. The Company also generates revenue within Germany, which was less than one percent of its total revenue for the three months ended August 31, 2012 and 2011. Long-lived assets in Germany are insignificant in relation to total long-lived assets of the Company as of August 31, 2012 and May 31, 2012.
Basis of presentation	*Basis of presentation:* The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to the Quarterly Report on Form 10-Q (“Form 10-Q”) and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statement presentation. The consolidated financial statements include the consolidated accounts of the Company with all significant intercompany transactions eliminated. In the opinion of management, the information furnished herein reflects all adjustments (consisting of items of a normal recurring nature), which are necessary for a fair presentation of the results for the interim period. These financial statements should be read in conjunction with the Company’s consolidated financial statements and related Notes to Consolidated Financial Statements presented in the Company’s Annual Report on Form 10-K (“Form 10-K”) as of and for the year ended May 31, 2012 (“fiscal 2012”). Operating results and cash flows for the three months ended August 31, 2012 are not necessarily indicative of the results that may be expected for other interim periods or the full fiscal year ending May 31, 2013 (“fiscal 2013”). The Company has evaluated subsequent events for potential recognition and/or disclosure through the date of issuance of these financial statements.
PEO workers' compensation insurance	*PEO workers’ compensation insurance:* Workers’ compensation insurance for PEO worksite employees is provided under a deductible workers’ compensation policy with a national insurance company. Reserves are established to provide for the estimated costs of paying claims underwritten by the Company. The Company’s maximum individual claims liability is $1.0 million under both its fiscal 2013 and fiscal 2012 policies. As of August 31, 2012 and May 31, 2012, the Company had recorded current liabilities of $6.7 million and $6.2 million, respectively, and long-term liabilities of $14.6 million and $19.0 million, respectively, on its Consolidated Balance Sheets for workers’ compensation costs. Estimating the ultimate cost of future claims is an uncertain and complex process based upon historical loss experience and actuarial loss projections, and is subject to change due to multiple factors, including economic trends, changes in legal liability law, and damage awards, all of which could materially impact the reserves as reported. Adjustments to previously established reserves are reflected in the results of operations for the period in which the adjustment is identified. Such adjustments could be significant, reflecting any combination of new and adverse or favorable trends.
Stock-based compensation costs	*Stock-based compensation costs:* The Company has issued stock-based awards to employees and directors consisting of stock options, restricted stock awards, restricted stock units, performance shares, and performance stock options. The Company accounts for all stock-based awards to employees and directors as compensation costs in the consolidated financial statements based on the fair value measured as of the date of grant. These costs are recognized as an expense in the Consolidated Statements of Income and Comprehensive Income over the requisite service period and increase additional paid-in capital. Stock-based compensation costs recognized were $6.4 million for the three months ended August 31, 2012, as compared with $6.6 million for the three months ended August 31, 2011. The methods and assumptions used in the determination of the fair value of stock-based awards are consistent with those described in the Company’s fiscal 2012 Form 10-K.
Reclassifications	*Reclassifications:* Certain prior period amounts have been reclassified to conform to the current period presentation and had no effect on reported consolidated earnings.
Recently adopted accounting pronouncements	*Recently adopted accounting pronouncements:* Effective June 1, 2012, the Company adopted the Financial Accounting Standards Board (“FASB”) authoritative guidance on the presentation of comprehensive income. This guidance requires the Company to present components of net income and comprehensive income in one continuous statement or in two separate, but consecutive statements. There are no changes to the components that are recognized in net income or other comprehensive income. The Company elected to present net income and comprehensive income in one continuous statement, as presented in this Form 10-Q.
Recently issued accounting pronouncements	*Recently issued accounting pronouncements:* In July 2012, the FASB issued updated guidance on the periodic testing of indefinite-lived intangible assets, other than goodwill, for impairment. This updated guidance will allow companies the option to first assess qualitative factors to determine if it is more-likely-than-not that an indefinite-lived intangible asset might be impaired and whether it is necessary to perform the quantitative impairment test required under current accounting standards. This guidance is applicable for reporting periods beginning after September 15, 2012, with early adoption permitted, and is applicable to the Company’s fiscal year beginning June 1, 2013. The Company currently does not have any indefinite-life intangible assets other than goodwill and does not expect the adoption of this guidance will have a material effect on its consolidated financial statements. Other recent authoritative guidance issued by the FASB (including technical corrections to the Codification), the American Institute of Certified Public Accountants, and the Securities and Exchange Commission did not, or are not expected to have a material effect on the Company’s consolidated financial statements.

Disclosure of accounting policy for estimating its liability as of the balance sheet date for the ultimate cost of settling reported and unreported claims incurred and claims adjustment expenses (including effects of inflation and other societal and economic factors).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 60

-Paragraph 60

-Subparagraph a, b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-PLI

-Paragraph 2, 34, 132, 133

-IssueDate 2006-09-01

-Chapter 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.13(b))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 13

-Subparagraph b

-Article 7

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 94-5

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-URI http://asc.fasb.org/subtopic&trid=2560295

+ Details

- Definition

Disclosure of accounting policy for stock option and stock incentive plans. This disclosure may include (1) the types of stock option or incentive plans sponsored by the entity (2) the groups that participate in (or are covered by) each plan (3) significant plan provisions and (4) how stock compensation is measured, and the methodologies and significant assumptions used to determine that measurement.

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