CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2012		Dec. 31, 2011
Income Statement
Net sales	$ 416,047		$ 329,156		$ 1,151,479		$ 1,044,265
Cost of sales	215,619	[1]	143,668	[1]	552,059	[1]	440,617	[1]
Gross profit	200,428		185,488		599,420		603,648
Operating expenses:
Research and development	71,377	[1]	44,256	[1]	184,285	[1]	134,937	[1]
Selling, general and administrative	69,368	[1]	51,087	[1]	196,727	[1]	158,603	[1]
Amortization of acquired intangible assets	39,711		2,678		71,615		8,161
Special charges (income)	2,559		(660)		24,953		(660)
Total operating expenses	183,015		97,361		477,580		301,041
Operating income	17,413		88,127		121,840		302,607
Losses (gains) on equity method investments	(229)		14		(382)		(60)
Other income (expense):
Interest income	3,813		4,374		11,889		12,408
Interest expense	(11,077)		(8,994)		(30,983)		(25,920)
Other, net	(228)		156		311		(1,262)
Income before income taxes	9,692		83,677		102,675		287,773
Income tax (benefit) provision	(481)		6,188		34,976		31,704
Net income	$ 10,173		$ 77,489		$ 67,699		$ 256,069
Basic net income per common share	$ 0.05		$ 0.40		$ 0.35		$ 1.34
Diluted net income per common share	$ 0.05		$ 0.38		$ 0.33		$ 1.26
Dividends declared per common share	$ 0.352		$ 0.348		$ 1.053		$ 1.041
Basic common shares outstanding	194,958		191,640		194,157		190,854
Diluted common shares outstanding	204,405		203,291		204,553		202,686

[1] Includes share-based compensation expense as follows:Cost of sales 1,834 1,369 5,758 4,376 Research and development 6,172 3,851 16,562 10,820Selling, general and administrative 6,114 4,742 22,339 13,274