Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Segment Reporting Information [Line Items]
Segment Net Sales	$ 338,911	$ 329,156	$ 340,602	$ 374,507	$ 379,985	$ 367,824	$ 382,271	$ 357,125	$ 1,383,176	$ 1,487,205	$ 947,729
Segment Gross Profit	193,873	183,779	194,994	219,748	225,591	216,397	225,005	207,443	792,394	874,436	534,242
Semiconductor products [Member]
Segment Reporting Information [Line Items]
Segment Net Sales									1,296,175	1,415,137	947,729
Segment Gross Profit									709,754	806,398	534,242
Technology licensing [Member]
Segment Reporting Information [Line Items]
Segment Net Sales									87,001	72,068	0
Segment Gross Profit									$ 82,640	$ 68,038	$ 0