Geographic and Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Segment Net Sales	$ 557,647	$ 540,344	$ 541,391	$ 533,952	$ 543,207	$ 528,710	$ 546,243	$ 528,876	$ 2,173,334	$ 2,147,036	$ 1,931,217
Segment Gross Profit	$ 302,779	$ 292,718	$ 300,950	$ 309,017	$ 313,632	$ 301,959	$ 307,454	$ 306,519	1,205,464	1,229,564	1,128,743
Semiconductor products [Member]
Segment Reporting Information [Line Items]
Segment Net Sales									2,084,210	2,057,443	1,836,639
Segment Gross Profit									1,116,340	1,139,971	1,034,165
Technology licensing [Member]
Segment Reporting Information [Line Items]
Segment Net Sales									89,124	89,593	94,578
Segment Gross Profit									$ 89,124	$ 89,593	$ 94,578