Client funds investments, maturity period.

No definition available.

Name:	adp_ClientFundsInvestmentsOriginalMaturityPeriod
Namespace Prefix:	adp_
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Balance Type:	na
Period Type:	duration

- Definition

Represent the Company's contractual obligations to remit funds to satisfy clients' payroll and tax payment obligations and are recorded on the Balance Sheet at the time that the Company impounds funds from clients.

+ References

No definition available.

+ Details

Name:	adp_ClientFundsObligations
Namespace Prefix:	adp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Earliest non-callable debt maturity date

+ References

No definition available.

+ Details

Name:	adp_EarliestNonCallableDebtMaturityDate
Namespace Prefix:	adp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Latest non-callable debt maturity date

+ References

No definition available.

+ Details

Name:	adp_LatestNonCallableDebtMaturityDate
Namespace Prefix:	adp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Length of longest cash flow of residential mortgages used as collateral for the Company's mortgage-backed securities (in years).

+ References

No definition available.

+ Details

Name:	adp_LengthOfLongestCashFlowOfResidentialMortgagesUsedAsCollateralForCompanySMortgageBackedSecuritiesInYears
Namespace Prefix:	adp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Length of shortest cash flow of residential mortgages used as collateral for companies mortgage backed securities (in years)

+ References

No definition available.

+ Details

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Namespace Prefix:	adp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of the available-for-sale securities were rated AAA or AA

+ References

No definition available.

+ Details

Name:	adp_PercentageOfAvailableForSaleSecuritiesWereRatedOr
Namespace Prefix:	adp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the excess of amortized cost basis over fair value of securities in a loss position and categorized neither as held-to-maturity nor trading securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph 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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The net amount of gross unrealized gains (losses) for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27357-111563

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount by which the fair value of an investment in debt and equity securities categorized as Available-for-sale is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

+ References

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-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 FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15C

-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 FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 22

-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.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The increase (decrease), resulting in a loss, in the difference between the fair value and the carrying value, or in the comparative fair values, of securities held at each balance sheet date, that was included in earnings for the period.

+ References

No definition available.

+ Details

Name:	us-gaap_UnrealizedLossOnSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Corporate Investments And Funds Held For Clients (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Dec. 31, 2011	Mar. 31, 2012	Jun. 30, 2011
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		$ 17,718.9	$ 16,927.5
Client funds obligations		29,207.0	24,591.1
Available-for-sale securities, continuous unrealized loss position, aggregate losses		(13.1)
Percentage of the available-for-sale securities were rated AAA or AA		85.00%
Client funds investments with original maturities		90 days or less
Earliest non-callable debt maturity date		April 2012
Latest non-callable debt maturity date		February 2022
Available-for-sale securities, gross unrealized gain (loss)	(5.8)
Impairment losses on available -for-sale securities	5.8	5.8
Required to sell securities unrealized loss		13.1
Length of shortest cash flow of residential mortgages used as collateral for companies mortgage backed securities (in years)		15 years
Length of longest cash flow of residential mortgages used as collateral for company's mortgage backed securities (in years)		30 years
Federal Home Loan Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		4,011.8	3,886.5
Federal Farm Credit Banks [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		1,151.4	914.0
Federal National Mortgage Association ("Fannie Mae") [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		533.3	702.4
Federal Home Loan Mortgage Corporation ("Freddie Mac") [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		387.8	759.1
Fixed Rate Credit Card [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		245.1	220.5
Rate Reduction [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		143.7	196.9
Asset-Backed Auto Loan Receivables [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		25.3	30.0
Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		134.9	146.5
Canadian Provincial Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		579.3	494.3
Corporate Bonds Backed By Federal Deposit Insurance Corporation's Temporary Liquidity Guarantee Program [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		55.3	129.1
Sovereign Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		353.8	328.8
Supranational Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities - fair value		$ 406.1	$ 360.1