Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Segment reporting information [Line Items]
Net sales	$ 482,372	$ 416,047	$ 1,437,833	$ 1,151,479
Gross Profit	282,720	200,428	838,157	599,420
Semiconductor products [Member]
Segment reporting information [Line Items]
Net sales	458,298	394,709	1,366,415	1,089,738
Gross Profit	258,646	179,090	766,739	537,679
Technology licensing [Member]
Segment reporting information [Line Items]
Net sales	24,074	21,338	71,418	61,741
Gross Profit	$ 24,074	$ 21,338	$ 71,418	$ 61,741