Stock Repurchase Activity (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Mar. 31, 2012
Treasury stock repurchase [Abstract]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	10.0
Repurchased shares under authorization (in shares)	7.5
Amount of repurchased shares under authorization	$ 234.7

This element represents the cumulative value of stock that has been repurchased under the current share repurchase authorization and have not been retired.

No definition available.

Name:	mchp_StockRepurchasedValueTotal
Namespace Prefix:	mchp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration