CONDENSED CONSOLIDATED STATEMENTS OF INCOME (unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Income Statement
Net sales	$ 462,792		$ 352,134
Cost of sales	196,218	[1]	147,337	[1]
Gross profit	266,574		204,797
Operating expenses:
Research and development	73,085	[1]	48,826	[1]
Selling, general and administrative	65,710	[1]	55,592	[1]
Amortization of acquired intangible assets	27,677		4,046
Special charges	1,701		0
Total operating expenses	168,173		108,464
Operating income	98,401		96,333
Losses on equity method investments	(260)		(121)
Other income (expense):
Interest income	3,925		4,332
Interest expense	(11,856)		(9,148)
Other income (expense), net	126		(532)
Income before income taxes	90,336		90,864
Income tax provision	11,757		12,154
Net income	$ 78,579		$ 78,710
Basic net income per common share	$ 0.40		$ 0.41
Diluted net income per common share	$ 0.37		$ 0.39
Dividends declared per common share	$ 0.3535		$ 0.3500
Basic common shares outstanding	196,950		193,452
Diluted common shares outstanding	212,266		203,700

[1] Includes share-based compensation expense as follows:Cost of sales 1,969 1,310 Research and development 5,690 4,032Selling, general and administrative 4,997 4,644