Business Acquisitions (Schedule of Purchased Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended	0 Months Ended
	Mar. 31, 2015	Jul. 17, 2014	Apr. 01, 2014
Developed Technology [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Asset, Amount	$ 144,700
In Process Research and Development [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Asset, Amount	29,100
Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Asset, Amount	68,800
Order or Production Backlog [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Asset, Amount	1,700
ISSC Technologies Corporation [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Asset, Amount		147,800
ISSC Technologies Corporation [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life		10 years
Acquired Finite-lived Intangible Asset, Amount		68,900
ISSC Technologies Corporation [Member] | In Process Research and Development [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life		10 years
Acquired Finite-lived Intangible Asset, Amount		27,200
ISSC Technologies Corporation [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life		3 years
Acquired Finite-lived Intangible Asset, Amount		51,100
ISSC Technologies Corporation [Member] | Order or Production Backlog [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life		1 year
Acquired Finite-lived Intangible Asset, Amount		600
Supertex Inc. [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Asset, Amount			89,600
Supertex Inc. [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			10 years
Acquired Finite-lived Intangible Asset, Amount			68,900
Supertex Inc. [Member] | In Process Research and Development [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			10 years
Acquired Finite-lived Intangible Asset, Amount			1,900
Supertex Inc. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			2 years
Acquired Finite-lived Intangible Asset, Amount			17,700
Supertex Inc. [Member] | Order or Production Backlog [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life			1 year
Acquired Finite-lived Intangible Asset, Amount			$ 1,100