Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 902,666	$ 834,366	$ 871,364	$ 799,411	$ 557,647	$ 540,344	$ 541,391	$ 533,952	$ 3,407,807	$ 2,173,334	$ 2,147,036
Gross profit	532,826	465,259	410,621	348,490	302,779	292,718	300,950	309,017	1,757,196	1,205,464	1,229,564
Operating income	154,087	118,074	62,760	(59,104)	79,946	76,132	74,948	121,319	275,817	352,345	425,620
Net income from continuing operations	$ 136,908	$ 107,175	$ 33,919	$ (113,363)	67,355	61,211	64,899	130,460	164,639	323,925	365,325
Less: Net loss attributable to noncontrolling interests					0	0	0	207	0	207	3,684
Net income attributable to Microchip Technology					$ 67,355	$ 61,211	$ 64,899	$ 130,667	$ 164,639	$ 324,132	$ 369,009
Net income attributable to Microchip Technology (in usd per share)	$ 0.57	$ 0.46	$ 0.14	$ (0.53)	$ 0.31	$ 0.28	$ 0.30	$ 0.60	$ 0.71	$ 1.49	$ 1.65
Loss on settlement of convertible debt	$ 43,900								$ 43,879	$ 0	$ 50,631