Geographic and Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Segment Net Sales	$ 493,384	$ 482,372	$ 492,669	$ 462,792	$ 430,144	$ 416,047	$ 383,298	$ 352,134	$ 1,931,217	$ 1,581,623	$ 1,383,176
Segment Gross Profit	290,586	282,720	288,863	266,574	239,039	200,428	194,195	204,797	1,128,743	838,459	799,294
Semiconductor products [Member]
Segment Reporting Information [Line Items]
Segment Net Sales									1,836,639	1,497,820	1,296,175
Segment Gross Profit									1,034,165	754,656	712,798
Technology licensing [Member]
Segment Reporting Information [Line Items]
Segment Net Sales									94,578	83,803	87,001
Segment Gross Profit									$ 94,578	$ 83,803	$ 86,496