Paychex (PAYX) 10-Q 20 Dec 13 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Nov. 30, 2013
Document and Entity Information [Abstract]	'
Entity Registrant Name	'PAYCHEX INC
Entity Central Index Key	'0000723531
Current Fiscal Year End Date	'--05-31
Entity Filer Category	'Large Accelerated Filer
Document Type	'10-Q
Document Period End Date	30-Nov-13
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q2
Amendment Flag	'false
Entity Common Stock, Shares Outstanding	364,212,329

Consolidated_Statements_of_Inc

Consolidated Statements of Income and Comprehensive Income (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Revenue:	'	'	'	'
Service revenue	$600.50	$559.40	$1,198.40	$1,127.50
Interest on funds held for clients	10	10	20	20.1
Total revenue	610.5	569.4	1,218.40	1,147.60
Expenses:	'	'	'	'
Operating expenses	167.7	163.6	332.4	327.1
Selling, general and administrative expenses	194.2	175.8	382.3	352.5
Total expenses	361.9	339.4	714.7	679.6
Operating income	248.6	230	503.7	468
Investment income, net	1.3	1.9	2.5	3.8
Income before income taxes	249.9	231.9	506.2	471.8
Income taxes	91.2	84	184.7	170.8
Net income	158.7	147.9	321.5	301
Other comprehensive income/(loss), net of tax:	'	'	'	'
Unrealized gains/(losses) on securities, net of tax	18.6	2.4	-8.3	2
Total other comprehensive income/(loss), net of tax	18.6	2.4	-8.3	2
Comprehensive income	$177.30	$150.30	$313.20	$303
Basic earnings per share	$0.43	$0.41	$0.88	$0.83
Diluted earnings per share	$0.43	$0.41	$0.88	$0.83
Weighted-average common shares outstanding	364.9	363.6	365.1	363.3
Weighted-average common shares outstanding, assuming dilution	366.4	364.4	366.5	364.1
Cash dividends per common share	$0.35	$0.33	$0.70	$0.65

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Nov. 30, 2013	31-May-13
In Millions, unless otherwise specified
ASSETS	'	'
Cash and cash equivalents	$213	$107.30
Corporate investments	250.4	398.2
Interest receivable	34.8	32.4
Accounts receivable, net of allowance for doubtful accounts	178.8	133.4
Deferred income taxes	0.1	2.3
Prepaid income taxes	31.6	49.9
Prepaid expenses and other current assets	43.1	36.6
Current assets before funds held for clients	751.8	760.1
Funds held for clients	3,912	4,072.50
Total current assets	4,663.80	4,832.60
Long-term corporate investments	375.9	369.1
Property and equipment, net of accumulated depreciation	351.4	346
Intangible assets, net of accumulated amortization	43.6	45.2
Goodwill	540	533.9
Deferred income taxes	36.1	34.1
Other long-term assets	8.6	2.8
Total assets	6,019.40	6,163.70
LIABILITIES	'	'
Accounts payable	36.4	42.7
Accrued compensation and related items	135.8	138.2
Deferred income taxes	16	8.1
Other current liabilities	41.3	39.5
Current liabilities before client fund obligations	229.5	228.5
Client fund obligations	3,889.60	4,039.70
Total current liabilities	4,119.10	4,268.20
Accrued income taxes	23.7	19.7
Deferred income taxes	61.6	53.3
Other long-term liabilities	54.6	48.8
Total liabilities	4,259	4,390
COMMITMENTS AND CONTINGENCIES - NOTE I	'	'
STOCKHOLDERS' EQUITY	'	'
Common stock, $0.01 par value; Authorized: 600.0 shares; Issued and outstanding: 364.2 shares as of November 30, 2013 and 365.4 shares as of May 31, 2013, respectively.	3.6	3.7
Additional paid-in capital	749.9	659.5
Retained earnings	993.2	1,088.50
Accumulated other comprehensive income	13.7	22
Total stockholders' equity	1,760.40	1,773.70
Total liabilities and stockholders' equity	$6,019.40	$6,163.70

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $)	Nov. 30, 2013	31-May-13
In Millions, except Per Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	600	600
Common stock, shares issued	364.2	365.4
Common stock, shares outstanding	364.2	365.4

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012
OPERATING ACTIVITIES	'	'
Net income	$321.50	$301
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization on property and equipment and intangible assets	50.4	48.3
Amortization of premiums and discounts on available-for-sale securities, net	34.4	27.1
Stock-based compensation costs	14.6	11.5
Provision for deferred income taxes	16	17.5
Provision for allowance for doubtful accounts	1.3	0.7
Net realized gains on sales of available-for-sale securities	-0.2	-0.3
Changes in operating assets and liabilities:	'	'
Interest receivable	-2.4	-0.4
Accounts receivable	-46.4	-27.5
Prepaid expenses and other current assets	11.7	-11
Accounts payable and other current liabilities	-6.7	-41.5
Net change in other assets and liabilities	6	0.6
Net cash provided by operating activities	400.2	326
INVESTING ACTIVITIES	'	'
Purchases of available-for-sale securities	-14,941.70	-12,222.30
Proceeds from sales and maturities of available-for-sale securities	15,755.30	12,249.80
Net change in funds held for clients' money market securities and other cash equivalents	-557.4	777.1
Purchases of property and equipment	-46.9	-54.5
Acquisition of business, net of cash acquired	-9.3	-12
Purchases of other assets	-5.7	-0.5
Net cash provided by investing activities	194.3	737.6
FINANCING ACTIVITIES	'	'
Net change in client fund obligations	-150.2	-829.8
Dividends paid	-255.7	-236.4
Repurchases of common shares	-159.1	0
Equity activity related to stock-based awards	76.2	16.4
Net cash used in financing activities	-488.8	-1,049.80
Increase in cash and cash equivalents	105.7	13.8
Cash and cash equivalents, beginning of period	107.3	108.8
Cash and cash equivalents, end of period	$213	$122.60

Description_of_Business_Basis_

Description of Business, Basis of Presentation, and Significant Accounting Policies	6 Months Ended
	Nov. 30, 2013
Accounting Policies [Abstract]	'
Description of Business, Basis of Presentation, and Significant Accounting Policies	'
	Description of Business, Basis of Presentation, and Significant Accounting Policies
	Description of business: Paychex, Inc. and its wholly owned subsidiaries (collectively, the “Company” or “Paychex”) is a leading provider of payroll, human resource, insurance, and benefits outsourcing solutions for small- to medium-sized businesses in the United States (“U.S.”). The Company also has operations 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 represented less than one percent of the Company's total revenue for the six months ended November 30, 2013 and 2012. Long-lived assets in Germany are insignificant in relation to total long-lived assets of the Company as of November 30, 2013 and May 31, 2013.
	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, 2013 (“fiscal 2013”). Operating results and cash flows for the six months ended November 30, 2013 are not necessarily indicative of the results that may be expected for other interim periods or the full fiscal year ending May 31, 2014 (“fiscal 2014”). 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: Workers’ compensation insurance for professional employer organization ("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 2014 and fiscal 2013 policies. As of November 30, 2013 and May 31, 2013, the Company had recorded current liabilities of $8.9 million and $6.8 million, respectively, and long-term liabilities of $14.0 million and $13.7 million, respectively, on its Consolidated Balance Sheets for PEO 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 in the consolidated financial statements. Accordingly, final claim settlements may vary from the present estimates, particularly when those payments may not occur until well into the future. The Company regularly reviews the adequacy of its estimated workers' compensation insurance reserves. 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: 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 over the requisite service period. Stock-based compensation costs recognized were $7.1 million and $14.6 million, respectively, for the three and six months ended November 30, 2013, as compared with $5.1 million and $11.5 million, respectively, for the three and six months ended November 30, 2012. 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 2013 Form 10-K.
	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: Effective June 1, 2013, the Company adopted Accounting Standards Update ("ASU") 2013-02, "Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income," issued by the Financial Accounting Standards Board (“FASB”). This authoritative guidance requires the reporting of the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income. There are no changes to the components that are recognized in net income or other comprehensive income. Adoption of this guidance did not have a material effect on the Company's consolidated financial statements.
	Effective June 1, 2013, the Company adopted ASU 2012-02, "Intangibles - Goodwill and Other (Topic 350): Testing Indefinite-Lived Intangible Assets for Impairment." This updated guidance allows 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. The Company currently does not have any indefinite-lived intangible assets other than goodwill, so adoption of this guidance did not have a material effect on its consolidated financial statements.
	Recently issued accounting pronouncements: In July 2013, the FASB issued ASU 2013-11, "Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists." This ASU provides explicit guidance regarding the presentation in the statement of financial position of an unrecognized tax benefit when net operating losses or tax credit carryforwards exist. It is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013, with early adoption permitted, and is applicable to the Company's fiscal year beginning June 1, 2014. The Company does not anticipate that 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 Accounting Standards 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.

Basic_and_Diluted_Earnings_Per

Basic and Diluted Earnings Per Share	6 Months Ended
	Nov. 30, 2013
Earnings Per Share [Abstract]	'
Basic and Diluted Earnings Per Share	'
	Basic and Diluted Earnings Per Share
	Basic and diluted earnings per share were calculated as follows:
		For the three months ended				For the six months ended
		November 30,				November 30,
	In millions, except per share amounts	2013		2012		2013		2012
	Basic earnings per share:
	Net income	$	158.7	$	147.9	$	321.5	$	301
	Weighted-average common shares outstanding	364.9		363.6		365.1		363.3
	Basic earnings per share	$	0.43	$	0.41	$	0.88	$	0.83
	Diluted earnings per share:
	Net income	$	158.7	$	147.9	$	321.5	$	301
	Weighted-average common shares outstanding	364.9		363.6		365.1		363.3
	Dilutive effect of common share equivalents	1.5		0.8		1.4		0.8
	Weighted-average common shares outstanding, assuming dilution	366.4		364.4		366.5		364.1
	Diluted earnings per share	$	0.43	$	0.41	$	0.88	$	0.83
	Weighted-average anti-dilutive common share equivalents	0.8		7.5		0.8		7.5
	Weighted-average common share equivalents that have an anti-dilutive impact are excluded from the computation of diluted earnings per share.
	For the three months ended November 30, 2013 and 2012, 0.9 million and 0.3 million shares, respectively, of the Company’s common stock were issued in connection with the exercise or vesting of stock-based awards. For the six months ended November 30, 2013 and 2012, 2.8 million and 1.1 million shares, respectively, of the Company’s common stock were issued in connection with the exercise or vesting of stock-based awards.
	In October 2012, the Company announced its program to repurchase up to $350 million of its common stock with authorization expiring on May 31, 2014. During the three months ended November 30, 2013, the Company repurchased 1.9 million shares for $75.2 million. During the six months ended November 30, 2013, the Company repurchased 4.0 million shares for $159.1 million. Shares repurchased are retired.

Investment_Income_Net_Notes

Investment Income, Net (Notes)	6 Months Ended
	Nov. 30, 2013
Investment Income, Net [Abstract]	'
Investment Income, Net [Text Block]	'
	Investment Income, Net
	Investment income, net, consisted of the following items:
		For the three months ended					For the six months ended
		November 30,					November 30,
	In millions	2013			2012		2013			2012
	Interest income on corporate funds	$	1.7		$	1.9	$	3.3		$	3.9
	Interest expense	(0.4		)	—		(0.8		)	(0.1		)
	Investment income, net	$	1.3		$	1.9	$	2.5		$	3.8

Funds_Held_for_Clients_and_Cor

Funds Held for Clients and Corporate Investments	6 Months Ended
	Nov. 30, 2013
Funds Held for Clients and Corporate Investments [Abstract]	'
Funds held for clients and corporate investments	'
	Funds Held for Clients and Corporate Investments
	Funds held for clients and corporate investments consisted of the following:
		30-Nov-13
	In millions	Amortized			Gross		Gross			Fair
		cost			unrealized		unrealized			value
					gains		losses
	Type of issue:
	Funds held for clients money market securities and other cash equivalents	$	1,695.10		$	—	$	—		$	1,695.10
	Available-for-sale securities:
	General obligation municipal bonds	1,640.10			23.6		(8.0		)	1,655.70
	Pre-refunded municipal bonds(1)	127.8			2.2		—			130
	Revenue municipal bonds	842.7			8.3		(4.6		)	846.4
	Variable rate demand notes	198.4			—		—			198.4
	Total available-for-sale securities	2,809.00			34.1		(12.6		)	2,830.50
	Other	10.8			1.9		—			12.7
	Total funds held for clients and corporate investments	$	4,514.90		$	36	$	(12.6	)	$	4,538.30
		May 31, 2013
	In millions	Amortized			Gross		Gross			Fair
		cost			unrealized		unrealized			value
					gains		losses
	Type of issue:
	Funds held for clients money market securities and other cash equivalents	$	1,137.70		$	—	$	—		$	1,137.70
	Available-for-sale securities:
	General obligation municipal bonds	1,432.90			27.4		(3.5		)	1,456.80
	Pre-refunded municipal bonds(1)	201			2.9		—			203.9
	Revenue municipal bonds	746.1			10.1		(2.2		)	754
	Variable rate demand notes	1,276.70			—		—			1,276.70
	Total available-for-sale securities	3,656.70			40.4		(5.7		)	3,691.40
	Other	9.5			1.2		—			10.7
	Total funds held for clients and corporate investments	$	4,803.90		$	41.6	$	(5.7	)	$	4,839.80
	(1)	Pre-refunded municipal bonds are secured by an escrow fund of U.S. government obligations.
	Included in money market securities and other cash equivalents as of November 30, 2013 and May 31, 2013 were money market funds and bank demand deposit accounts.
	Classification of investments on the Consolidated Balance Sheets is as follows:
	In millions	30-Nov-13			31-May-13
	Funds held for clients	$	3,912.00		$	4,072.50
	Corporate investments	250.4			398.2
	Long-term corporate investments	375.9			369.1
	Total funds held for clients and corporate investments	$	4,538.30		$	4,839.80
	The Company’s available-for-sale securities reflected a net unrealized gain of $21.5 million as of November 30, 2013 compared with a net unrealized gain of $34.7 million as of May 31, 2013. Included in the net unrealized gain as of November 30, 2013 and May 31, 2013, there were 192 and 147 available-for-sale securities in an unrealized loss position, respectively. The securities in an unrealized loss position were as follows:
		30-Nov-13
		Less than twelve months					More than twelve months					Total
	In millions	Gross			Fair		Gross			Fair		Gross			Fair
		unrealized			value		unrealized			Value		unrealized			Value
		losses					losses					losses
	Type of issue:
	General obligation municipal bonds	$	(7.9	)	$	453.9	$	(0.1	)	$	4.7	$	(8.0	)	$	458.6
	Pre-refunded municipal bonds	—			10.2		—			—		—			10.2
	Revenue municipal bonds	(4.5		)	302.4		(0.1		)	7.1		(4.6		)	309.5
	Total	$	(12.4	)	$	766.5	$	(0.2	)	$	11.8	$	(12.6	)	$	778.3
		31-May-13
		Less than twelve months					More than twelve months					Total
	In millions	Gross			Fair		Gross			Fair		Gross			Fair
		unrealized			value		unrealized			Value		unrealized			Value
		losses					losses					losses
	Type of issue:
	General obligation municipal bonds	$	(3.5	)	$	349.2	$	—		$	—	$	(3.5	)	$	349.2
	Pre-refunded municipal bonds	—			3.1		—			—		—			3.1
	Revenue municipal bonds	(2.2		)	225.3		—			2.1		(2.2		)	227.4
	Total	$	(5.7	)	$	577.6	$	—		$	2.1	$	(5.7	)	$	579.7
	The Company regularly reviews its investment portfolios to determine if any investment is other-than-temporarily impaired due to changes in credit risk or other potential valuation concerns. The Company believes that the investments it held as of November 30, 2013, that had unrealized losses totaling $12.6 million, were not other-than-temporarily impaired. The Company believes that it is probable that the principal and interest will be collected in accordance with the contractual terms, and that the unrealized losses on these securities were due to changes in interest rates, and were not due to increased credit risk or other valuation concerns. A substantial portion of the securities in an unrealized loss position as of November 30, 2013 and May 31, 2013 held an AA rating or better. The Company does not intend to sell these investments until the recovery of their amortized cost basis or maturity, and further believes that it is not more-likely-than-not that it will be required to sell these investments prior to that time. The Company’s assessment that an investment is not other-than-temporarily impaired could change in the future due to new developments or changes in the Company’s strategies or assumptions related to any particular investment.
	Realized gains and losses on the sales of securities are determined by specific identification of the amortized cost basis of each security. On the Consolidated Statements of Income and Comprehensive Income, realized gains and losses from funds held for clients are included in interest on funds held for clients and realized gains and losses from corporate investments are included in investment income, net. Realized gains were minimal for the three months ended November 30, 2013 and were $0.2 million, for the six months ended November 30, 2013. Realized gains were $0.1 million and $0.3 million, respectively, for the three and six months ended November 30, 2012. There were no realized losses recognized in any of the respective periods.
	The amortized cost and fair value of available-for-sale securities that had stated maturities as of November 30, 2013 are shown below by contractual maturity. Expected maturities can differ from contractual maturities because borrowers may have the right to prepay obligations without prepayment penalties.
		30-Nov-13
In millions	Amortized			Fair
	cost			value
Maturity date:
Due in one year or less	$	337.4		$	340.2
Due after one year through three years	742.1			760.2
Due after three years through five years	736.7			745.9
Due after five years	992.8			984.2
Total	$	2,809.00		$	2,830.50
Variable rate demand notes are primarily categorized as due after five years in the table above as the contractual maturities on these securities are typically 20 to 30 years. Although these securities are issued as long-term securities, they are priced and traded as short-term instruments because of the liquidity provided through the tender feature.

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Nov. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	Fair value is defined as the price that would be received to sell an asset, or paid to transfer a liability (an exit price), in an orderly transaction between market participants at the measurement date. The accounting standards related to fair value measurements include a hierarchy for information and valuations used in measuring fair value that is broken down into three levels based on reliability, as follows:
	•	Level 1 valuations are based on quoted prices in active markets for identical instruments that the Company can access at the measurement date.
	•	Level 2 valuations are based on inputs other than quoted prices included in Level 1 that are observable for the instrument, either directly or indirectly, for substantially the full term of the asset or liability including the following:
	•	quoted prices for similar, but not identical, instruments in active markets;
	•	quoted prices for identical or similar instruments in markets that are not active;
	•	inputs other than quoted prices that are observable for the instrument; or
	•	inputs that are derived principally from or corroborated by observable market data by correlation or other means.
	•	Level 3 valuations are based on information that is unobservable and significant to the overall fair value measurement.
	The carrying values of cash and cash equivalents, accounts receivable, net of allowance for doubtful accounts, and accounts payable approximate fair value due to the short maturities of these instruments. Marketable securities included in funds held for clients and corporate investments consist primarily of securities classified as available-for-sale and are recorded at fair value on a recurring basis.
	The Company’s financial assets and liabilities measured at fair value on a recurring basis were as follows:
		November 30, 2013
	In millions	Carrying		Quoted		Significant		Significant
		value		prices  in		other		unobservable
		(Fair value)		active		observable		inputs
				markets		inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets:
	Available-for-sale securities:
	General obligation municipal bonds	$	1,655.70	$	—	$	1,655.70	$	—
	Pre-refunded municipal bonds	130		—		130		—
	Revenue municipal bonds	846.4		—		846.4		—
	Variable rate demand notes	198.4		—		198.4		—
	Total available-for-sale securities	$	2,830.50	$	—	$	2,830.50	$	—
	Other securities	$	12.7	12.7		$	—	$	—
	Liabilities:
	Other long-term liabilities	$	12.7	$	12.7	$	—	$	—
		31-May-13
	In millions	Carrying		Quoted		Significant		Significant
		value		prices  in		other		unobservable
		(Fair value)		active		observable		inputs
				markets		inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets:
	Available-for-sale securities:
	General obligation municipal bonds	$	1,456.80	$	—	$	1,456.80	$	—
	Pre-refunded municipal bonds	203.9		—		203.9		—
	Revenue municipal bonds	754		—		754		—
	Variable rate demand notes	1,276.70		—		1,276.70		—
	Total available-for-sale securities	$	3,691.40	$	—	$	3,691.40	$	—
	Other securities	$	10.7	10.7		$	—	$	—
	Liabilities:
	Other long-term liabilities	$	10.7	$	10.7	$	—	$	—
	In determining the fair value of its assets and liabilities, the Company predominately uses the market approach. Available-for-sale securities included in Level 2 are valued utilizing inputs obtained from an independent pricing service. To determine the fair value of the Company’s Level 2 available-for-sale investments, a variety of inputs are utilized, including benchmark yields, reported trades, non-binding broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, reference data, new issue data, and monthly payment information. The Company has not adjusted the prices obtained from the independent pricing service.
	Other securities are mutual fund investments, consisting of participants’ eligible deferral contributions under the Company’s non-qualified and unfunded deferred compensation plans. The related liability is reported as other long-term liabilities. The mutual funds are valued based on quoted market prices in active markets.
	The preceding methods described may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, although the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

Property_and_Equipment_Net_of_

Property and Equipment, Net of Accumulated Depreciation	6 Months Ended
	Nov. 30, 2013
Property, Plant and Equipment [Abstract]	'
Property and Equipment, Net of Accumulated Depreciation	'
	Property and Equipment, Net of Accumulated Depreciation
	The components of property and equipment, at cost, consisted of the following:
	In millions	30-Nov-13		31-May-13
	Land and improvements	$	8.1	$	8.1
	Buildings and improvements	100.6		99.2
	Data processing equipment	177.6		175.6
	Software	326.8		290.1
	Furniture, fixtures, and equipment	145.5		145.2
	Leasehold improvements	101.3		99.5
	Construction in progress	18.3		32.8
	Total property and equipment, gross	878.2		850.5
	Less: Accumulated depreciation and amortization	526.8		504.5
	Property and equipment, net of accumulated depreciation	$	351.4	$	346
	Depreciation expense was $22.2 million and $42.9 million for the three and six months ended November 30, 2013, respectively, compared to $19.5 million and $38.9 million, respectively, for the three and six months ended November 30, 2012.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets, Net of Accumulated Amortization	6 Months Ended
	Nov. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets, Net of Accumulated Amortization	'
	Goodwill and Intangible Assets, Net of Accumulated Amortization
	The Company had goodwill balances on its Consolidated Balance Sheets of $540.0 million and $533.9 million as of November 30, 2013 and May 31, 2013, respectively. The increase in goodwill was due to an immaterial business acquisition.
	The Company has certain intangible assets with finite lives. The components of intangible assets, at cost, consisted of the following:
	In millions	30-Nov-13		31-May-13
	Client lists	$	236.2	$	231
	Other intangible assets	2.6		2.4
	Total intangible assets, gross	238.8		233.4
	Less: Accumulated amortization	195.2		188.2
	Intangible assets, net of accumulated amortization	$	43.6	$	45.2
	Amortization expense relating to intangible assets was $3.8 million and $7.5 million for the three and six months ended November 30, 2013, respectively, as compared with $4.7 million and $9.4 million for the three and six months ended November 30, 2012.
	As of November 30, 2013, the estimated amortization expense relating to intangible asset balances for the full year fiscal 2014 and the following four fiscal years is as follows:
	In millions	Estimated
	Fiscal year ending May 31,	amortization
		expense
	2014	$	15.7
	2015	$	12
	2016	$	8.8
	2017	$	6.3
	2018	$	4.2

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income/(Loss)	6 Months Ended
	Nov. 30, 2013
Equity [Abstract]	'
Accumulated Other Comprehensive Income/(Loss)	'
	Accumulated Other Comprehensive Income/(Loss)
	The change in unrealized gains and losses, net of applicable taxes, related to available-for-sale securities is the primary component reported in accumulated other comprehensive income/(loss) in the Consolidated Balance Sheets.
	The changes in accumulated other comprehensive income/(loss) are as follows:
		For the three months ended						For the six months ended
		November 30,						November 30,
	In millions	2013			2012			2013			2012
	Beginning balance	$	(4.9	)	$	37.3		$	22		$	37.7
	Other comprehensive income/(loss):
	Unrealized gains/(losses) on available-for-sale securities, net of tax	18.6			2.5			(8.2		)	2.2
	Reclassification adjustment for the net gain on sale of available-for-sale securities realized in net income, net of tax	—			(0.1		)	(0.1		)	(0.2		)
	Total other comprehensive income/(loss), net of tax	18.6			2.4			(8.3		)	2
	Ending balance	$	13.7		$	39.7		$	13.7		$	39.7
	The total tax impact in other comprehensive income/(loss) for the three and six months ended November 30, 2013 was tax expense of $10.8 million and tax benefit of $4.8 million, respectively. The total tax impact in other comprehensive income/(loss) for the three and six months ended November 30, 2012 was tax expense of $1.6 million and $1.3 million, respectively.
	Reclassification adjustments out of accumulated other comprehensive income/(loss) are for realized gains on the sales of available-for-sale securities. For the three and six months ended November 30, 2013 and 2012, these reclassification adjustments impacted interest on funds held for clients on the Consolidated Statements of Income and Comprehensive Income.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Nov. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Lines of credit: As of November 30, 2013, the Company had unused borrowing capacity available under four uncommitted, secured, short-term lines of credit at market rates of interest with financial institutions as follows:
	Financial institution	Amount available	Expiration date
	JP Morgan Chase Bank, N.A.	$350 million	February 28, 2014
	Bank of America, N.A.	$250 million	February 28, 2014
	PNC Bank, National Association	$150 million	February 28, 2014
	Wells Fargo Bank, National Association	$150 million	February 28, 2014
	The primary uses of the lines of credit would be to meet short-term funding requirements related to deposit account overdrafts and client fund obligations arising from electronic payment transactions on behalf of clients in the ordinary course of business, if necessary. No amounts were outstanding against these lines of credit as of, or during the six months ended, November 30, 2013.
	The financial institutions are also parties to the Company's credit facility and irrevocable standby letters of credit, which are discussed below.
	Credit facility: In June 2013, the Company entered into a committed, unsecured, five-year syndicated credit facility, expiring on June 21, 2018. Under the credit facility, Paychex of New York LLP (the "Borrower") may, subject to certain restrictions, borrow up to $500 million to meet short-term funding requirements. The obligations under this facility have been guaranteed by the Company and certain of its subsidiaries. The outstanding obligations under this credit facility will bear interest at competitive rates based on options provided to the Borrower. Upon expiration of the commitment in June 2018, any borrowings outstanding will mature and be payable on such date. During the six months ended November 30, 2013, the Company borrowed $25.0 million and $175.0 million, each for one day, at an interest rate of 3.25%. There were no amounts outstanding against this credit facility as of November 30, 2013.
	Certain lenders under this credit facility, and their respective affiliates, have performed, and may in the future perform for the Company and its subsidiaries, various commercial banking, investment banking, underwriting, and other financial advisory services, for which they have received, and will continue to receive in the future, customary fees and expenses.
	Letters of credit: As of November 30, 2013 and May 31, 2013, the Company had irrevocable standby letters of credit available totaling $35.5 million and $36.8 million, respectively, required to secure commitments for certain insurance policies. The letters of credit expire at various dates between July 2014 and December 2014. Upon draw down of funds, the letters of credit are collateralized by securities held in the Company’s investment portfolios. No amounts were outstanding on these letters of credit as of, or during the six months ended, November 30, 2013.
	Other commitments: The Company enters into various purchase commitments with vendors in the ordinary course of business. The Company had outstanding commitments to purchase approximately $6.4 million and $9.9 million of capital assets as of November 30, 2013 and May 31, 2013, respectively.
	In the normal course of business, the Company makes representations and warranties that guarantee the performance of services under service arrangements with clients. Historically, there have been no material losses related to such guarantees. In addition, the Company has entered into indemnification agreements with its officers and directors, which require it to defend and, if necessary, indemnify these individuals for certain pending or future claims as they relate to their services provided to the Company.
	Paychex currently self-insures the deductible portion of various insured exposures under certain employee benefit plans. The Company’s estimated loss exposure under these insurance arrangements is recorded in other current liabilities on the Consolidated Balance Sheets. Historically, the amounts accrued have not been material and are not material as of the reporting date. The Company also maintains insurance coverage in addition to its purchased primary insurance policies for gap coverage for employment practices liability, errors and omissions, warranty liability, theft and embezzlement, cyber threats, and acts of terrorism; and capacity for deductibles and self-insured retentions through its captive insurance company.
	Contingencies: The Company is subject to various claims and legal matters that arise in the normal course of its business. These include disputes or potential disputes related to breach of contract, breach of fiduciary duty, employment-related claims, tax claims, and other matters.
	The Company’s management currently believes that resolution of any outstanding legal matters will not have a material adverse effect on the Company’s financial position or results of operations. However, legal matters are subject to inherent uncertainties and there exists the possibility that the ultimate resolution of these matters could have a material adverse impact on the Company’s financial position and results of operations in the period in which any such effect is recorded.

Description_of_Business_Basis_1

Description of Business, Basis of Presentation, and Significant Accounting Policies (Policies)	6 Months Ended
	Nov. 30, 2013
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, insurance, and benefits outsourcing solutions for small- to medium-sized businesses in the United States (“U.S.”). The Company also has operations 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 represented less than one percent of the Company's total revenue for the six months ended November 30, 2013 and 2012. Long-lived assets in Germany are insignificant in relation to total long-lived assets of the Company as of November 30, 2013 and May 31, 2013.
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, 2013 (“fiscal 2013”). Operating results and cash flows for the six months ended November 30, 2013 are not necessarily indicative of the results that may be expected for other interim periods or the full fiscal year ending May 31, 2014 (“fiscal 2014”). 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 professional employer organization ("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 2014 and fiscal 2013 policies. As of November 30, 2013 and May 31, 2013, the Company had recorded current liabilities of $8.9 million and $6.8 million, respectively, and long-term liabilities of $14.0 million and $13.7 million, respectively, on its Consolidated Balance Sheets for PEO 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 in the consolidated financial statements. Accordingly, final claim settlements may vary from the present estimates, particularly when those payments may not occur until well into the future. The Company regularly reviews the adequacy of its estimated workers' compensation insurance reserves. 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 over the requisite service period. Stock-based compensation costs recognized were $7.1 million and $14.6 million, respectively, for the three and six months ended November 30, 2013, as compared with $5.1 million and $11.5 million, respectively, for the three and six months ended November 30, 2012. 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 2013 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.
New accounting pronouncements	'
	Recently adopted accounting pronouncements: Effective June 1, 2013, the Company adopted Accounting Standards Update ("ASU") 2013-02, "Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income," issued by the Financial Accounting Standards Board (“FASB”). This authoritative guidance requires the reporting of the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income. There are no changes to the components that are recognized in net income or other comprehensive income. Adoption of this guidance did not have a material effect on the Company's consolidated financial statements.
	Effective June 1, 2013, the Company adopted ASU 2012-02, "Intangibles - Goodwill and Other (Topic 350): Testing Indefinite-Lived Intangible Assets for Impairment." This updated guidance allows 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. The Company currently does not have any indefinite-lived intangible assets other than goodwill, so adoption of this guidance did not have a material effect on its consolidated financial statements.
	Recently issued accounting pronouncements: In July 2013, the FASB issued ASU 2013-11, "Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists." This ASU provides explicit guidance regarding the presentation in the statement of financial position of an unrecognized tax benefit when net operating losses or tax credit carryforwards exist. It is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013, with early adoption permitted, and is applicable to the Company's fiscal year beginning June 1, 2014. The Company does not anticipate that 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 Accounting Standards 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.

Basic_and_Diluted_Earnings_Per1

Basic and Diluted Earnings Per Share (Tables)	6 Months Ended
	Nov. 30, 2013
Earnings Per Share [Abstract]	'
Basic and diluted earnings per share	'
	Basic and diluted earnings per share were calculated as follows:
		For the three months ended				For the six months ended
		November 30,				November 30,
	In millions, except per share amounts	2013		2012		2013		2012
	Basic earnings per share:
	Net income	$	158.7	$	147.9	$	321.5	$	301
	Weighted-average common shares outstanding	364.9		363.6		365.1		363.3
	Basic earnings per share	$	0.43	$	0.41	$	0.88	$	0.83
	Diluted earnings per share:
	Net income	$	158.7	$	147.9	$	321.5	$	301
	Weighted-average common shares outstanding	364.9		363.6		365.1		363.3
	Dilutive effect of common share equivalents	1.5		0.8		1.4		0.8
	Weighted-average common shares outstanding, assuming dilution	366.4		364.4		366.5		364.1
	Diluted earnings per share	$	0.43	$	0.41	$	0.88	$	0.83
	Weighted-average anti-dilutive common share equivalents	0.8		7.5		0.8		7.5

Investment_Income_Net_Tables

Investment Income, Net (Tables)	6 Months Ended
	Nov. 30, 2013
Investment Income, Net [Abstract]	'
Schedule of Investment Income, Net [Table Text Block]	'
	Investment income, net, consisted of the following items:
		For the three months ended					For the six months ended
		November 30,					November 30,
	In millions	2013			2012		2013			2012
	Interest income on corporate funds	$	1.7		$	1.9	$	3.3		$	3.9
	Interest expense	(0.4		)	—		(0.8		)	(0.1		)
	Investment income, net	$	1.3		$	1.9	$	2.5		$	3.8

Funds_Held_for_Clients_and_Cor1

Funds Held for Clients and Corporate Investments (Tables)	6 Months Ended
	Nov. 30, 2013
Funds Held for Clients and Corporate Investments [Abstract]	'
Funds held for clients and corporate investments	'
	Funds held for clients and corporate investments consisted of the following:
		30-Nov-13
	In millions	Amortized			Gross		Gross			Fair
		cost			unrealized		unrealized			value
					gains		losses
	Type of issue:
	Funds held for clients money market securities and other cash equivalents	$	1,695.10		$	—	$	—		$	1,695.10
	Available-for-sale securities:
	General obligation municipal bonds	1,640.10			23.6		(8.0		)	1,655.70
	Pre-refunded municipal bonds(1)	127.8			2.2		—			130
	Revenue municipal bonds	842.7			8.3		(4.6		)	846.4
	Variable rate demand notes	198.4			—		—			198.4
	Total available-for-sale securities	2,809.00			34.1		(12.6		)	2,830.50
	Other	10.8			1.9		—			12.7
	Total funds held for clients and corporate investments	$	4,514.90		$	36	$	(12.6	)	$	4,538.30
		May 31, 2013
	In millions	Amortized			Gross		Gross			Fair
		cost			unrealized		unrealized			value
					gains		losses
	Type of issue:
	Funds held for clients money market securities and other cash equivalents	$	1,137.70		$	—	$	—		$	1,137.70
	Available-for-sale securities:
	General obligation municipal bonds	1,432.90			27.4		(3.5		)	1,456.80
	Pre-refunded municipal bonds(1)	201			2.9		—			203.9
	Revenue municipal bonds	746.1			10.1		(2.2		)	754
	Variable rate demand notes	1,276.70			—		—			1,276.70
	Total available-for-sale securities	3,656.70			40.4		(5.7		)	3,691.40
	Other	9.5			1.2		—			10.7
	Total funds held for clients and corporate investments	$	4,803.90		$	41.6	$	(5.7	)	$	4,839.80
	(1)	Pre-refunded municipal bonds are secured by an escrow fund of U.S. government obligations.
Classification of investments on the Consolidated Balance Sheets	'
	Classification of investments on the Consolidated Balance Sheets is as follows:
	In millions	30-Nov-13			31-May-13
	Funds held for clients	$	3,912.00		$	4,072.50
	Corporate investments	250.4			398.2
	Long-term corporate investments	375.9			369.1
	Total funds held for clients and corporate investments	$	4,538.30		$	4,839.80
Securities in an unrealized loss position	'
	The securities in an unrealized loss position were as follows:
		30-Nov-13
		Less than twelve months					More than twelve months					Total
	In millions	Gross			Fair		Gross			Fair		Gross			Fair
		unrealized			value		unrealized			Value		unrealized			Value
		losses					losses					losses
	Type of issue:
	General obligation municipal bonds	$	(7.9	)	$	453.9	$	(0.1	)	$	4.7	$	(8.0	)	$	458.6
	Pre-refunded municipal bonds	—			10.2		—			—		—			10.2
	Revenue municipal bonds	(4.5		)	302.4		(0.1		)	7.1		(4.6		)	309.5
	Total	$	(12.4	)	$	766.5	$	(0.2	)	$	11.8	$	(12.6	)	$	778.3
		31-May-13
		Less than twelve months					More than twelve months					Total
	In millions	Gross			Fair		Gross			Fair		Gross			Fair
		unrealized			value		unrealized			Value		unrealized			Value
		losses					losses					losses
	Type of issue:
	General obligation municipal bonds	$	(3.5	)	$	349.2	$	—		$	—	$	(3.5	)	$	349.2
	Pre-refunded municipal bonds	—			3.1		—			—		—			3.1
	Revenue municipal bonds	(2.2		)	225.3		—			2.1		(2.2		)	227.4
	Total	$	(5.7	)	$	577.6	$	—		$	2.1	$	(5.7	)	$	579.7
Amortized cost and fair value of available-for-sale securities by contractual maturity	'
	The amortized cost and fair value of available-for-sale securities that had stated maturities as of November 30, 2013 are shown below by contractual maturity. Expected maturities can differ from contractual maturities because borrowers may have the right to prepay obligations without prepayment penalties.
		30-Nov-13
	In millions	Amortized			Fair
		cost			value
	Maturity date:
	Due in one year or less	$	337.4		$	340.2
	Due after one year through three years	742.1			760.2
	Due after three years through five years	736.7			745.9
	Due after five years	992.8			984.2
	Total	$	2,809.00		$	2,830.50

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Nov. 30, 2013
Fair Value Disclosures [Abstract]	'
Financial assets and liabilities measured at fair value on a recurring basis	'
	The Company’s financial assets and liabilities measured at fair value on a recurring basis were as follows:
		November 30, 2013
	In millions	Carrying		Quoted		Significant		Significant
		value		prices  in		other		unobservable
		(Fair value)		active		observable		inputs
				markets		inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets:
	Available-for-sale securities:
	General obligation municipal bonds	$	1,655.70	$	—	$	1,655.70	$	—
	Pre-refunded municipal bonds	130		—		130		—
	Revenue municipal bonds	846.4		—		846.4		—
	Variable rate demand notes	198.4		—		198.4		—
	Total available-for-sale securities	$	2,830.50	$	—	$	2,830.50	$	—
	Other securities	$	12.7	12.7		$	—	$	—
	Liabilities:
	Other long-term liabilities	$	12.7	$	12.7	$	—	$	—
		31-May-13
	In millions	Carrying		Quoted		Significant		Significant
		value		prices  in		other		unobservable
		(Fair value)		active		observable		inputs
				markets		inputs		(Level 3)
				(Level 1)		(Level 2)
	Assets:
	Available-for-sale securities:
	General obligation municipal bonds	$	1,456.80	$	—	$	1,456.80	$	—
	Pre-refunded municipal bonds	203.9		—		203.9		—
	Revenue municipal bonds	754		—		754		—
	Variable rate demand notes	1,276.70		—		1,276.70		—
	Total available-for-sale securities	$	3,691.40	$	—	$	3,691.40	$	—
	Other securities	$	10.7	10.7		$	—	$	—
	Liabilities:
	Other long-term liabilities	$	10.7	$	10.7	$	—	$	—

Property_and_Equipment_Net_of_1

Property and Equipment, Net of Accumulated Depreciation (Tables)	6 Months Ended
	Nov. 30, 2013
Property, Plant and Equipment [Abstract]	'
Components of property and equipment, at cost	'
	The components of property and equipment, at cost, consisted of the following:
	In millions	30-Nov-13		31-May-13
	Land and improvements	$	8.1	$	8.1
	Buildings and improvements	100.6		99.2
	Data processing equipment	177.6		175.6
	Software	326.8		290.1
	Furniture, fixtures, and equipment	145.5		145.2
	Leasehold improvements	101.3		99.5
	Construction in progress	18.3		32.8
	Total property and equipment, gross	878.2		850.5
	Less: Accumulated depreciation and amortization	526.8		504.5
	Property and equipment, net of accumulated depreciation	$	351.4	$	346

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets, Net of Accumulated Amortization (Tables)	6 Months Ended
	Nov. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Components of intangible assets, at cost	'
	The components of intangible assets, at cost, consisted of the following:
	In millions	30-Nov-13		31-May-13
	Client lists	$	236.2	$	231
	Other intangible assets	2.6		2.4
	Total intangible assets, gross	238.8		233.4
	Less: Accumulated amortization	195.2		188.2
	Intangible assets, net of accumulated amortization	$	43.6	$	45.2
Estimated future amortization expense relating to intangible assets	'
	As of November 30, 2013, the estimated amortization expense relating to intangible asset balances for the full year fiscal 2014 and the following four fiscal years is as follows:
	In millions	Estimated
	Fiscal year ending May 31,	amortization
		expense
	2014	$	15.7
	2015	$	12
	2016	$	8.8
	2017	$	6.3
	2018	$	4.2

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income/(Loss) (Tables)	6 Months Ended
	Nov. 30, 2013
Equity [Abstract]	'
Changes in accumulated other comprehensive income/(loss)	'
	The changes in accumulated other comprehensive income/(loss) are as follows:
		For the three months ended						For the six months ended
		November 30,						November 30,
	In millions	2013			2012			2013			2012
	Beginning balance	$	(4.9	)	$	37.3		$	22		$	37.7
	Other comprehensive income/(loss):
	Unrealized gains/(losses) on available-for-sale securities, net of tax	18.6			2.5			(8.2		)	2.2
	Reclassification adjustment for the net gain on sale of available-for-sale securities realized in net income, net of tax	—			(0.1		)	(0.1		)	(0.2		)
	Total other comprehensive income/(loss), net of tax	18.6			2.4			(8.3		)	2
	Ending balance	$	13.7		$	39.7		$	13.7		$	39.7

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	6 Months Ended
	Nov. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Lines of credit facility unused borrowing capacity	'
	As of November 30, 2013, the Company had unused borrowing capacity available under four uncommitted, secured, short-term lines of credit at market rates of interest with financial institutions as follows:
	Financial institution	Amount available	Expiration date
	JP Morgan Chase Bank, N.A.	$350 million	February 28, 2014
	Bank of America, N.A.	$250 million	February 28, 2014
	PNC Bank, National Association	$150 million	February 28, 2014
	Wells Fargo Bank, National Association	$150 million	February 28, 2014

Description_of_Business_Basis_2

Description of Business, Basis of Presentation, and Significant Accounting Policies (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012	31-May-13
Description of Business, Basis of Presentation, and Significant Accounting Policies (Textual)	'	'	'	'	'
Disclosure on geographic areas, Description of revenue from external customers	'	'	'revenue within Germany, which represented less than one percent of the Company's total revenue	'revenue within Germany, which represented less than one percent of the Company's total revenue	'
Disclosure on geographic areas, Long-lived assets	'	'	'Long-lived assets in Germany are insignificant in relation to total long-lived assets of the Company	'	'Long-lived assets in Germany are insignificant in relation to total long-lived assets of the Company
Maximum individual workers' compensation claims liability	'	'	$1	'	$1
Workers' compensation insurance costs in current liabilities	8.9	'	8.9	'	6.8
Workers' compensation insurance costs in long-term liabilities	14	'	14	'	13.7
Stock-based compensation costs recognized	$7.10	$5.10	$14.60	$11.50	'

Basic_and_Diluted_Earnings_Per2

Basic and Diluted Earnings Per Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Basic earnings per share:	'	'	'	'
Net income	$158.70	$147.90	$321.50	$301
Weighted-average common shares outstanding	364.9	363.6	365.1	363.3
Basic earnings per share	$0.43	$0.41	$0.88	$0.83
Diluted earnings per share:	'	'	'	'
Net income	$158.70	$147.90	$321.50	$301
Weighted-average common shares outstanding	364.9	363.6	365.1	363.3
Dilutive effect of common share equivalents	1.5	0.8	1.4	0.8
Weighted-average common shares outstanding, assuming dilution	366.4	364.4	366.5	364.1
Diluted earnings per share	$0.43	$0.41	$0.88	$0.83
Weighted-average anti-dilutive common share equivalents	0.8	7.5	0.8	7.5

Basic_and_Diluted_Earnings_Per3

Basic and Diluted Earnings Per Share (Details Textual) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Basic And Diluted Earnings Per Share (Textual)	'	'	'	'
Common stock issued in connection with the exercise or vesting of stock-based awards	0.9	0.3	2.8	1.1
Stock repurchase program, Authorized amount	'	'	$350	'
Stock repurchased and retired during period, Shares	1.9	'	4	'
Stock repurchased and retired during period, Value	$75.20	'	$159.10	'

Investment_Income_Net_Details

Investment Income, Net (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Investment Income, Net [Abstract]	'	'	'	'
Interest income on corporate funds	$1.70	$1.90	$3.30	$3.90
Interest expense	-0.4	0	-0.8	-0.1
Investment income, net	$1.30	$1.90	$2.50	$3.80

Funds_Held_for_Clients_and_Cor2

Funds Held for Clients and Corporate Investments (Details) (USD $)	Nov. 30, 2013		31-May-13
In Millions, unless otherwise specified
Type of issue:	'		'
Funds held for clients money market securities and other cash equivalents, Amortized cost	$1,695.10		$1,137.70
Funds held for clients money market securities and other cash equivalents, Gross unrealized gains	0		0
Funds held for clients money market securities and other cash equivalents, Gross unrealized losses	0		0
Funds held for clients money market securities and other cash equivalents, Fair value	1,695.10		1,137.70
Available-for-sale securities:	'		'
Amortized cost	2,809		3,656.70
Gross unrealized gains	34.1		40.4
Gross unreailzed losses	-12.6		-5.7
Fair value	2,830.50		3,691.40
Other, Amortized cost	10.8		9.5
Other, Gross unrealized gains	1.9		1.2
Other, Gross unrealized losses	0		0
Other, Fair value	12.7		10.7
Total funds held for clients and corporate investments, Amortized cost	4,514.90		4,803.90
Total funds held for clients and corporate investments, Gross unrealized gains	36		41.6
Total funds held for clients and corporate investments, Gross unrealized losses	-12.6		-5.7
Total funds held for clients and corporate investments, Fair value	4,538.30		4,839.80
General obligation municipal bonds [Member]	'		'
Available-for-sale securities:	'		'
Amortized cost	1,640.10		1,432.90
Gross unrealized gains	23.6		27.4
Gross unreailzed losses	-8		-3.5
Fair value	1,655.70		1,456.80
Pre-refunded municipal bonds [Member]	'		'
Available-for-sale securities:	'		'
Amortized cost	127.8	[1]	201	[1]
Gross unrealized gains	2.2	[1]	2.9	[1]
Gross unreailzed losses	0	[1]	0	[1]
Fair value	130	[1]	203.9	[1]
Revenue municipal bonds [Member]	'		'
Available-for-sale securities:	'		'
Amortized cost	842.7		746.1
Gross unrealized gains	8.3		10.1
Gross unreailzed losses	-4.6		-2.2
Fair value	846.4		754
Variable rate demand notes [Member]	'		'
Available-for-sale securities:	'		'
Amortized cost	198.4		1,276.70
Gross unrealized gains	0		0
Gross unreailzed losses	0		0
Fair value	$198.40		$1,276.70
[1]	Pre-refunded municipal bonds are secured by an escrow fund of U.S. government obligations.

Funds_Held_for_Clients_and_Cor3

Funds Held for Clients and Corporate Investments (Details 1) (USD $)	Nov. 30, 2013	31-May-13
In Millions, unless otherwise specified
Classification of investments on the Consolidated Balance Sheets	'	'
Funds held for clients	$3,912	$4,072.50
Corporate investments	250.4	398.2
Long-term corporate investments	375.9	369.1
Total funds held for clients and corporate investments, Fair value	4,538.30	4,839.80
Securities in an unrealized loss position	'	'
Less than twelve months, Gross unrealized losses	-12.4	-5.7
Less than twelve months, Fair value	766.5	577.6
Twelve months or longer, Gross unrealized losses	-0.2	0
Twelve months or longer, Fair value	11.8	2.1
Total, Gross unrealized losses	-12.6	-5.7
Total, Fair value	778.3	579.7
General obligation municipal bonds [Member]	'	'
Securities in an unrealized loss position	'	'
Less than twelve months, Gross unrealized losses	-7.9	-3.5
Less than twelve months, Fair value	453.9	349.2
Twelve months or longer, Gross unrealized losses	-0.1	0
Twelve months or longer, Fair value	4.7	0
Total, Gross unrealized losses	-8	-3.5
Total, Fair value	458.6	349.2
Pre-refunded municipal bonds [Member]	'	'
Securities in an unrealized loss position	'	'
Less than twelve months, Gross unrealized losses	0	0
Less than twelve months, Fair value	10.2	3.1
Twelve months or longer, Gross unrealized losses	0	0
Twelve months or longer, Fair value	0	0
Total, Gross unrealized losses	0	0
Total, Fair value	10.2	3.1
Revenue municipal bonds [Member]	'	'
Securities in an unrealized loss position	'	'
Less than twelve months, Gross unrealized losses	-4.5	-2.2
Less than twelve months, Fair value	302.4	225.3
Twelve months or longer, Gross unrealized losses	-0.1	0
Twelve months or longer, Fair value	7.1	2.1
Total, Gross unrealized losses	-4.6	-2.2
Total, Fair value	$309.50	$227.40

Funds_Held_for_Clients_and_Cor4

Funds Held for Clients and Corporate Investments (Details 2) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012	31-May-13
	Security		Security		Security
Maturity Date:	'	'	'	'	'
Due in one year or less, Amortized cost	$337.40	'	$337.40	'	'
Due in one year or less, Fair value	340.2	'	340.2	'	'
Due after one year through three years, Amortized cost	742.1	'	742.1	'	'
Due after one year through three years, Fair value	760.2	'	760.2	'	'
Due after three years through five years, Amortized cost	736.7	'	736.7	'	'
Due after three years through five years, Fair value	745.9	'	745.9	'	'
Due after five years, Amortized cost	992.8	'	992.8	'	'
Due after five years, Fair value	984.2	'	984.2	'	'
Total, Amortized cost	2,809	'	2,809	'	'
Fair value	2,830.50	'	2,830.50	'	3,691.40
Funds Held for Clients and Corporate Investments (Textual)	'	'	'	'	'
Net unrealized gain on available-for-sale securities	21.5	'	21.5	'	34.7
Number of available-for-sale securities in an unrealized loss position	192	'	192	'	147
Gross realized gains	0	0.1	0.2	0.3	'
Gross realized losses	$0	$0	$0	$0	'
Minimum maturity period for VRDNs primarily categorized as due after five years (in years)	'20 years	'	'20 years	'	'
Maximum maturity period for VRDNs, primarily categorized as due after five years (in years)	'30 years	'	'30 years	'	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Nov. 30, 2013	31-May-13
In Millions, unless otherwise specified
Available-for-sale securities:	'	'
Available-for-sale securities	$2,830.50	$3,691.40
Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	2,830.50	3,691.40
Other securities	12.7	10.7
Liabilities:	'	'
Other long-term liabilities	12.7	10.7
General obligation municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	1,655.70	1,456.80
Pre-refunded municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	130	203.9
Revenue municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	846.4	754
Variable rate demand notes [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	198.4	1,276.70
Quoted prices in active markets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Other securities	12.7	10.7
Liabilities:	'	'
Other long-term liabilities	12.7	10.7
Quoted prices in active markets (Level 1) [Member] | General obligation municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Quoted prices in active markets (Level 1) [Member] | Pre-refunded municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Quoted prices in active markets (Level 1) [Member] | Revenue municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Quoted prices in active markets (Level 1) [Member] | Variable rate demand notes [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Significant other observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	2,830.50	3,691.40
Other securities	0	0
Liabilities:	'	'
Other long-term liabilities	0	0
Significant other observable Inputs (Level 2) [Member] | General obligation municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	1,655.70	1,456.80
Significant other observable Inputs (Level 2) [Member] | Pre-refunded municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	130	203.9
Significant other observable Inputs (Level 2) [Member] | Revenue municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	846.4	754
Significant other observable Inputs (Level 2) [Member] | Variable rate demand notes [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	198.4	1,276.70
Significant unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Other securities	0	0
Liabilities:	'	'
Other long-term liabilities	0	0
Significant unobservable Inputs (Level 3) [Member] | General obligation municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Significant unobservable Inputs (Level 3) [Member] | Pre-refunded municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Significant unobservable Inputs (Level 3) [Member] | Revenue municipal bonds [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	0	0
Significant unobservable Inputs (Level 3) [Member] | Variable rate demand notes [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Available-for-sale securities:	'	'
Available-for-sale securities	$0	$0

Property_and_Equipment_Net_of_2

Property and Equipment, Net of Accumulated Depreciation (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012	31-May-13
Components of property and equipment, at cost	'	'	'	'	'
Land and improvements	$8.10	'	$8.10	'	$8.10
Buildings and improvements	100.6	'	100.6	'	99.2
Data processing equipment	177.6	'	177.6	'	175.6
Software	326.8	'	326.8	'	290.1
Furniture, fixtures, and equipment	145.5	'	145.5	'	145.2
Leasehold improvements	101.3	'	101.3	'	99.5
Construction in progress	18.3	'	18.3	'	32.8
Total property and equipment, gross	878.2	'	878.2	'	850.5
Less: Accumulated depreciation and amortization	526.8	'	526.8	'	504.5
Property and equipment, net of accumulated depreciation	351.4	'	351.4	'	346
Property and Equipment, Net of Accumulated Depreciation (Textual)	'	'	'	'	'
Depreciation expense	$22.20	$19.50	$42.90	$38.90	'

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets, Net of Accumulated Amortization (Details) (USD $)	Nov. 30, 2013	31-May-13
In Millions, unless otherwise specified
Components of intangible assets, at cost	'	'
Client lists	$236.20	$231
Other intangible assets	2.6	2.4
Total intangible assets, gross	238.8	233.4
Less: Accumulated amortization	195.2	188.2
Intangible assets, net of accumulated amortization	43.6	45.2
Estimated future amortization expense relating to intangible assets	'	'
Fiscal year ending May 31, 2014	15.7	'
Fiscal year ending May 31, 2015	12	'
Fiscal year ending May 31, 2016	8.8	'
Fiscal year ending May 31, 2017	6.3	'
Fiscal year ending May 31, 2018	$4.20	'

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets, Net of Accumulated Amortization (Details Textual) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012	31-May-13
Goodwill and Intangible Assets, Net of Accumulated Amortization (Textual)	'	'	'	'	'
Goodwill	$540	'	$540	'	$533.90
Amortization expense relating to intangible assets	$3.80	$4.70	$7.50	$9.40	'

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income/(Loss) (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Equity [Abstract]	'	'	'	'
Accumulated other comprehensive income/(loss),Beginning balance	($4.90)	$37.30	$22	$37.70
Other comprehensive income/(loss):	'	'	'	'
Unrealized gains/(losses) on available-for-sale securities, net of tax	18.6	2.5	-8.2	2.2
Reclassification adjustment for the net gain on sale of available-for-sale securities realized in net income, net of tax	0	-0.1	-0.1	-0.2
Total other comprehensive income/(loss), net of tax	18.6	2.4	-8.3	2
Accumulated other comprehensive income/(loss),Ending balance	13.7	39.7	13.7	39.7
Accumulated Other Comprehensive Income/(Loss) (Textual)	'	'	'	'
Other comprehensive income/(loss), tax expense/(benefit)	$10.80	$1.60	($4.80)	$1.30

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (Line of Credit [Member], USD $)	6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2013
JP Morgan Chase Bank, N.A. [Member]	'
Lines of credit	'
Amount available	$350
Expiration date	28-Feb-14
Bank of America, N.A. [Member]	'
Lines of credit	'
Amount available	250
Expiration date	28-Feb-14
PNC Bank, National Association [Member]	'
Lines of credit	'
Amount available	150
Expiration date	28-Feb-14
Wells Fargo Bank, National Association [Member]	'
Lines of credit	'
Amount available	$150
Expiration date	28-Feb-14

Commitments_and_Contingencies_2

Commitments and Contingencies (Details Textual) (USD $)	Nov. 30, 2013	31-May-13	Nov. 30, 2013	Nov. 30, 2013	Aug. 31, 2013	Nov. 30, 2013	Nov. 30, 2013	31-May-13
			Line of Credit [Member]	Revolving Credit Facility [Member]	Revolving Credit Facility [Member]	Revolving Credit Facility [Member]	Standby Letters of Credit [Member]	Standby Letters of Credit [Member]
Line of Credit Facility [Line Items]	'	'	'	'	'	'	'	'
Maximum amount outstanding during period	'	'	'	$175,000,000	$25,000,000	'	'	'
Interest rate on amount borrowed	'	'	'	3.25%	3.25%	'	'	'
Maximum borrowing capacity	'	'	'	500,000,000	'	500,000,000	'	'
Expiration date	'	'	'	'	'	21-Jun-18	'	'
Amount outstanding	'	'	0	0	'	0	'	'
Amount available	'	'	'	'	'	'	35,500,000	36,800,000
Expiration date range of letters of credit	'	'	'	'	'	'	'July 2014 and December 2014	'
Irrevocable stand by letters of credit amount outstanding	'	'	'	'	'	'	0	'
Commitments and Contingencies (Textual)	'	'	'	'	'	'	'	'
Commitments to purchase capital assets	$6,400,000	$9,900,000	'	'	'	'	'	'