Derivative Instruments (Details)	12 Months Ended
Mar. 31, 2012
Derivative Instrument Detail [Abstract]
Percentage of company sales denominated in U.S. dollars (in hundredths)	99.00%

The percentage of the Company's transactions that are denominated in U.S. dollars.

No definition available.

Name:	mchp_PercentageOfCompanySalesDenominatedInUsDollars
Namespace Prefix:	mchp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration