Comprehensive Income (Schedule Of Reclassifications Of Recognized Transactions Out Of AOCI) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net					$ 13,742	$ 5,898	$ (404)
Income tax provision					19,418	(37,073)	(24,788)
Net income attributable to Microchip Technology	99,402	86,057	93,641	89,909	369,009	395,281	127,389
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net					18,706	2,371	394
Income tax provision					(12)	(776)	(51)
Net income attributable to Microchip Technology					$ 18,694	$ 1,595	$ 343