Debt Instrument Additional Basis On Variable Rate Base

No definition available.

Name:	mchp_DebtInstrumentAdditionalBasisOnVariableRateBase
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Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument Interest Rate Spread On Overdue Amounts In Event Of Default

+ References

No definition available.

+ Details

Name:	mchp_DebtInstrumentInterestRateSpreadOnOverdueAmountsInEventOfDefault
Namespace Prefix:	mchp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument Interest Rate Spread On Overdue Principal In Event Of Default

+ References

No definition available.

+ Details

Name:	mchp_DebtInstrumentInterestRateSpreadOnOverduePrincipalInEventOfDefault
Namespace Prefix:	mchp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility Increase Option - An increase option in the credit agreement which provides, subject to certain requirements, the Company to arrange with existing lenders and/or new lenders to provide up to an aggregate of $250 million in additional commitments, whether for revolving loans or term loans.

+ References

No definition available.

+ Details

Name:	mchp_LineOfCreditFacilityIncreaseOption
Namespace Prefix:	mchp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period For Leverage Ratio To Determine Interest Rate Spread

+ References

No definition available.

+ Details

Name:	mchp_PeriodForLeverageRatioToDetermineInterestRateSpread
Namespace Prefix:	mchp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentDescriptionOfVariableRateBasis
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The cost of borrowed funds accounted for as interest that was charged against earnings during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.9)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 34

-Paragraph 21

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 9

-Article 9

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

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Chapter V

-Section 563c.102

-Paragraph 9

-Subsection II

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_InterestExpense
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

Reflects when the credit facility terminates, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 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 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects when the credit facility first became available, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LineOfCreditFacilityLineItems
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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

Credit facility (Details) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended		6 Months Ended					6 Months Ended				6 Months Ended
Credit facility (Details) (USD $)	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Credit Agreement Maturity August 12, 2016 [Member]	Sep. 30, 2012 Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Credit Agreement Maturity August 12, 2016 [Member]	Sep. 30, 2012 Line of Credit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Line of Credit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Line of Credit Facility Foreign Currency Sublimit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Line of Credit Facility Swingline Loan Sublimit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Line of Credit Facility Letter of Credit Sublimit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Sep. 30, 2012 Debt Instrument Interest Rate Option1 [Member] Line of Credit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Debt Instrument Interest Rate Option1 [Member] Line of Credit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Debt Instrument Interest Rate Option1 [Member] Minimum [Member] Line of Credit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Debt Instrument Interest Rate Option1 [Member] Maximum [Member] Line of Credit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Sep. 30, 2012 Debt Instrument Interest Rate Option 2 [Member] Line of Credit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Debt Instrument Interest Rate Option 2 [Member] Line of Credit [Member] Credit Agreement Maturity August 12, 2016 [Member]	Aug. 12, 2011 Debt Instrument Interest Rate Option 2 [Member] Minimum [Member] Line of Credit [Member]	Aug. 12, 2011 Debt Instrument Interest Rate Option 2 [Member] Maximum [Member] Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Initiation Date						August 12, 2011
Line of Credit Facility, Maximum Borrowing Capacity							$ 750,000,000			$ 100,000,000	$ 15,000,000	$ 25,000,000
Line of Credit Facility, Expiration Date						August 12, 2016
Line of Credit Facility Increase Option							250,000,000
Line of Credit Facility, Amount Outstanding					600,000,000	600,000,000
Debt Instrument, Basis Spread on Variable Rate															0.50%	1.50%			1.50%	2.50%
Debt Instrument, Description of Variable Rate Basis													the highest of JPMorgan Chase Bank, N.A.'s prime rate, the federal funds rate plus a margin equal to 0.50% and the adjusted LIBOR rate for a 1-month interest period plus a margin equal to 1.00%				adjusted LIBOR rate (based on one, two, three, or six-month interest periods)
Period For Leverage Ratio To Determine Interest Rate Spread								preceding four fiscal quarter period
Interest Expense	$ 10,758,000	$ 8,911,000	$ 19,906,000	$ 16,926,000	$ 2,300,000
Debt Instrument Additional Basis On Variable Rate Base														0.50%				1.00%
Debt Instrument Interest Rate Spread On Overdue Principal In Event Of Default									2.00%
Debt Instrument Interest Rate Spread On Overdue Amounts In Event Of Default									2.00%