Business Acquisitions (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Mar. 31, 2013
Business Acquisition, Purchase Price Allocation [Abstract]
Contingent consideration	$ 20,492	$ 19,100
SMSC Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Aug. 02, 2012
Business Acquisition, Purchase Price Allocation [Abstract]
Cash and cash equivalents	180,925	180,925
Accounts recevable, net	58,441	58,441
Inventories	86,244	86,244
Prepaid expenses	5,617	5,617
Deferred tax assets	15,843	15,843
Other current assets	17,578	17,578
Property, plant and equipment	35,608	35,608
Long-term investments	24,275	24,275
Goodwill	165,592	169,065
Intangible assets, net	10,214	10,214
Purchased intangible assets	517,800	517,800
Other assets	3,835	3,835
Total assets acquired	1,121,972	1,125,445
Accounts payable	(28,035)	(28,035)
Accrued liabilities	(62,247)	(62,038)
Deferred income on shipments to distributors	(11,376)	(11,376)
Long-term income tax payable	(72,781)	(72,781)
Deferred tax liability	(16,682)	(21,079)
Other liabilities	(11,250)	(10,535)
Total liabilities assumed	(202,371)	(205,844)
Purchase price allocated	919,601	919,601
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments [Abstract]
Goodwill	(3,473)
Total assets acquired	(3,473)
Accrued liabilities	(209)
Deferred tax liabilty	4,397
Other liabilities	(715)
Total liabilities assumed	$ (3,473)