Geographic and Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Segment Reporting Information [Line Items]
Segment Net Sales	$ 430,144	$ 416,047	$ 383,298	$ 352,134	$ 338,911	$ 329,156	$ 340,602	$ 374,507	$ 1,581,623	$ 1,383,176	$ 1,487,205
Segment Gross Profit	239,039	200,428	194,195	204,797	195,646	185,488	196,703	221,457	838,459	799,294	881,251
Semiconductor products [Member]
Segment Reporting Information [Line Items]
Segment Net Sales									1,497,820	1,296,175	1,415,137
Segment Gross Profit									754,656	712,798	809,183
Technology licensing [Member]
Segment Reporting Information [Line Items]
Segment Net Sales									83,803	87,001	72,068
Segment Gross Profit									$ 83,803	$ 86,496	$ 72,068