Business Acquisitions (Details) (USD $)	9 Months Ended			0 Months Ended	9 Months Ended			9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013	Nov. 23, 2013 Eqcologic Acquisition [Member]	Dec. 31, 2013 Eqcologic Acquisition [Member]	Nov. 21, 2013 Eqcologic Acquisition [Member]	Nov. 20, 2013 Eqcologic Acquisition [Member]	Dec. 31, 2013 SMSC Acquisition [Member]	Mar. 31, 2013 SMSC Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition					Nov. 21, 2013			Aug. 02, 2012
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage							18.30%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain	$ 2,438,000	$ 0		$ 2,438,000
Business Acquisition, Percentage of Voting Interests Acquired						81.70%
Business Combination, Consideration Transferred						9,000,000
Weighted average useful life of finite lived intangible assets (in years)					8 years
Business Acquisition, Purchase Price Allocation [Abstract]
Cash and cash equivalents								180,925,000	180,925,000
Accounts recevable, net								58,441,000	58,441,000
Inventories								86,244,000	86,244,000
Prepaid expenses								5,617,000	5,617,000
Deferred tax assets								15,843,000	15,843,000
Other current assets								17,578,000	17,578,000
Property, plant and equipment, net								35,608,000	35,608,000
Long-term investments								24,275,000	24,275,000
Goodwill						6,400,000		165,592,000	169,065,000
Intangible assets, net								10,214,000	10,214,000
Purchased intangible assets						4,100,000		517,800,000	517,800,000
Other assets								3,835,000	3,835,000
Total assets acquired								1,121,972,000	1,125,445,000
Accounts payable								(28,035,000)	(28,035,000)
Accrued liabilities								(62,247,000)	(62,038,000)
Deferred income on shipments to distributors								(11,376,000)	(11,376,000)
Long-term income tax payable								(72,781,000)	(72,781,000)
Deferred tax liability								(16,682,000)	(21,079,000)
Other liabilities								(11,250,000)	(10,535,000)
Contingent consideration	0		19,100,000
Total liabilities assumed								(202,371,000)	(205,844,000)
Purchase price allocated								919,601,000	919,601,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments [Abstract]
Goodwill								(3,473,000)
Total assets acquired								(3,473,000)
Accrued liabilities								(209,000)
Deferred tax liabilty								4,397,000
Other liabilities								(715,000)
Total liabilities assumed								$ (3,473,000)