Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Segment reporting information [Line Items]
Net sales	$ 528,876	$ 462,792
Gross Profit	306,519	266,574
Semiconductor products [Member]
Segment reporting information [Line Items]
Net sales	508,439	440,274
Gross Profit	286,082	244,056
Technology licensing [Member]
Segment reporting information [Line Items]
Net sales	20,437	22,518
Gross Profit	$ 20,437	$ 22,518