Business Acquisitions (Tables)

12 Months Ended

Mar. 31, 2015

Schedule of Purchase Price Allocation [Table Text Block]

The table below represents the preliminary allocation of the purchase price, including adjustments to the purchase price allocation from the originally reported figures at September 30, 2014, to the net assets acquired based on their estimated fair values as of July 17, 2014, as well as the associated estimated useful lives of the acquired intangible assets at that date (amounts in thousands):



Assets acquired	Previously Reported September 30, 2014			Adjustments			March 31, 2015
Cash and cash equivalents	$	15,120		$	—		$	15,120
Short-term investments	27,063			—			27,063
Accounts receivable, net	8,792			—			8,792
Inventories	19,160			(2,618		)	16,542
Prepaid expenses and other current assets	2,501			—			2,501
Property, plant and equipment, net	2,637			—			2,637
Goodwill	152,243			2,156			154,399
Purchased intangible assets ⁽¹⁾	147,800			—			147,800
Other assets	1,370			—			1,370
Total assets acquired	376,686			(462		)	376,224

Liabilities assumed
Accounts payable	(9,860		)	—			(9,860		)
Other current liabilities	(16,997		)	462			(16,535		)
Long-term income tax payable	(4,402		)	—			(4,402		)
Deferred tax liability	(25,126		)	—			(25,126		)
Other long-term liabilities	(245		)	—			(245		)
Total liabilities assumed	(56,630		)	462			(56,168		)
Net assets acquired including noncontrolling interest	320,056			—			320,056
Less: noncontrolling interest	(52,467		)	—			(52,467		)
Net assets acquired	$	267,589		$	—		$	267,589

Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]



⁽¹⁾ Purchased Intangible Assets	Useful Life	April 1, 2014
	(in years)	(in thousands)
Core/developed technology	10	$	68,900
In-process technology	10	27,200
Customer-related	3	51,100
Backlog	1	600
		$	147,800

Business Acquisition, Pro Forma Information [Table Text Block]

The following unaudited pro-forma consolidated results of operations for the years ended ended March 31, 2015 and 2014 assume the ISSC acquisition occurred as of April 1, 2013. Pro-forma adjustments mainly consist of acquired inventory fair value costs and amortization of purchased intangible assets. The pro-forma results of operations are presented for informational purposes only and are not indicative of the results of operations that would have been achieved if the acquisition had taken place on April 1, 2013 or of results that may occur in the future (amounts in thousands):



	Year Ended March 31,
	2015		2014
Net sales	$	2,169,390	$	1,998,647
Net income attributable to Microchip Technology	367,428		364,169
Net income attributable to Microchip Technology common stockholders per share - basic	$	1.83	$	1.84
Net income attributable to Microchip Technology common stockholders per share - diluted	$	1.64	$	1.67

Supertex Inc. [Member]

Business Acquisition [Line Items]

Schedule of Purchase Price Allocation [Table Text Block]

The table below represents the allocation of the purchase price, including adjustments to the purchase price allocation from the originally reported figures at June 30, 2014, to the net assets acquired based on their estimated fair values as of April 1, 2014 (amounts in thousands):



Assets acquired	Previously Reported June 30, 2014			Adjustments			March 31, 2015
Cash and cash equivalents	$	14,790		$	—		$	14,790
Short-term investments	140,984			—			140,984
Accounts receivable, net	7,047			—			7,047
Inventories	27,630			—			27,630
Prepaid expenses	1,493			—			1,493
Deferred tax assets	3,997			(1,541		)	2,456
Other current assets	16,113			(3,488		)	12,625
Property, plant and equipment, net	15,679			—			15,679
Goodwill	133,713			9,447			143,160
Purchased intangible assets ⁽¹⁾	89,600						89,600
Other assets	325			—			325
Total assets acquired	451,371			4,418			455,789

Liabilities assumed
Accounts payable	(8,481		)	—			(8,481		)
Accrued liabilities	(19,345		)	121			(19,224		)
Long-term income tax payable	(3,796		)	—			(3,796		)
Deferred tax liability	(27,972		)	(4,539		)	(32,511		)
Total liabilities assumed	(59,594		)	(4,418		)	(64,012		)
Net assets acquired	$	391,777		$	—		$	391,777

Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]



⁽¹⁾ Purchased Intangible Assets	Useful Life	April 1, 2014
	(in years)	(in thousands)
Core/developed technology	10	$	68,900
In-process technology	10	1,900
Customer-related	2	17,700
Backlog	1	1,100
		$	89,600

Business Acquisition, Pro Forma Information [Table Text Block]

The following unaudited pro-forma consolidated results of operations for the years ended March 31, 2015 and 2014 assume the Supertex acquisition occurred as of April 1, 2013. Pro-forma adjustments mainly consist of acquired inventory fair value costs and amortization of purchased intangible assets. The pro-forma results of operations are presented for informational purposes only and are not indicative of the results of operations that would have been achieved if the acquisition had taken place on April 1, 2013 or of results that may occur in the future (amounts in thousands):



	Year Ended March 31,
	2015		2014
Net sales	$	2,149,505	$	1,996,819
Net income	391,573		353,381
Basic earnings per share	$	1.95	$	1.78
Diluted earnings per share	$	1.75	$	1.62

SMSC Acquisition [Member]

Business Acquisition [Line Items]

Schedule of Purchase Price Allocation [Table Text Block]

The table below represents the allocation of the purchase price to the net assets acquired based on their estimated fair values as of August 2, 2012. The purchase price allocation was finalized as of August 2, 2013 (amounts in thousands):



Assets acquired
Cash and cash equivalents	$	180,925
Accounts receivable, net	58,441
Inventories	86,244
Prepaid expenses	5,617
Deferred tax assets	15,843
Other current assets	17,578
Property, plant and equipment, net	35,608
Long-term investments	24,275
Goodwill	165,592
Intangible assets, net	10,214
Purchased intangible assets	517,800
Other assets	3,835
Total assets acquired	1,121,972

Liabilities assumed
Accounts payable	(28,035		)
Accrued liabilities	(62,247		)
Deferred income on shipments to distributors	(11,376		)
Long-term income tax payable	(72,781		)
Deferred tax liability	(16,682		)
Other liabilities	(11,250		)
Total liabilities assumed	(202,371		)
Purchase price allocated	$	919,601