Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 557,647	$ 540,344	$ 541,391	$ 533,952	$ 543,207	$ 528,710	$ 546,243	$ 528,876	$ 2,173,334	$ 2,147,036	$ 1,931,217
Gross profit	302,779	292,718	300,950	309,017	313,632	301,959	307,454	306,519	1,205,464	1,229,564	1,128,743
Operating income	79,946	76,132	74,948	121,319	110,347	98,009	101,318	115,946	352,345	425,620	458,864
Net income	67,355	61,211	64,899	130,460	98,580	84,798	92,038	89,909	323,925	365,325	395,281
Less: Net loss attributable to noncontrolling interests	0	0	0	207	822	1,259	1,603	0	207	3,684	0
Net income attributable to Microchip Technology	$ 67,355	$ 61,211	$ 64,899	$ 130,667	$ 99,402	$ 86,057	$ 93,641	$ 89,909	$ 324,132	$ 369,009	$ 395,281
Diluted net income per common share attributable to Microchip Technology stockholders	$ 0.31	$ 0.28	$ 0.30	$ 0.60	$ 0.45	$ 0.39	$ 0.42	$ 0.40	$ 1.49	$ 1.65	$ 1.82
Loss on retirement of junior convertible debentures									$ 0	$ 50,631	$ 0