CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net sales	$ 3,407,807	$ 2,173,334	$ 2,147,036
Cost of sales	1,650,611	967,870	917,472
Gross profit	1,757,196	1,205,464	1,229,564
Operating expenses:
Research and development	545,293	372,596	349,543
Selling, general and administrative	499,811	301,670	274,815
Amortization of acquired intangible assets	337,667	174,896	176,746
Special charges and other, net	98,608	3,957	2,840
Operating expenses	1,481,379	853,119	803,944
Operating income	275,817	352,345	425,620
Losses on equity method investments	(222)	(345)	(317)
Other income (expense):
Interest income	3,079	24,447	19,527
Interest expense	(146,346)	(104,018)	(62,034)
Loss on settlement of convertible debt	(43,879)	0	(50,631)
Other income, net	1,338	8,864	13,742
Income before income taxes	89,787	281,293	345,907
Income tax benefit	(80,805)	(42,632)	(19,418)
Net income from continuing operations	170,592	323,925	365,325
Discontinued operations:
Loss from discontinued operations	(7,514)	0	0
Income tax benefit	(1,561)	0	0
Net loss from discontinued operations	(5,953)	0	0
Net income from continuing operations	164,639	323,925	365,325
Less: Net loss attributable to noncontrolling interests	0	207	3,684
Net income attributable to Microchip Technology	$ 164,639	$ 324,132	$ 369,009
Basic net income per common share attributable to Microchip Technology stockholders
Net income from continuing operations (in usd per share)	$ 0.79	$ 1.59	$ 1.84
Net loss from discontinued operations (in usd per share)	(0.03)	0.00	0.00
Net income attributable to Microchip Technology (in usd per share)	0.76	1.59	1.84
Diluted net income per common share attributable to Microchip Technology stockholders
Net income from continuing operations (in usd per share)	0.73	1.49	1.65
Net loss from discontinued operations (in usd per share)	(0.02)	0.00	0.00
Net income attributable to Microchip Technology (in usd per share)	0.71	1.49	1.65
Dividends declared per common share	$ 1.441	$ 1.433	$ 1.425
Basic common shares outstanding	217,196	203,384	200,937
Diluted common shares outstanding	234,806	217,388	223,561