CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) [Abstract]
Net sales	$ 796,853	$ 751,766
Contract revenue	31,918	65,835
Interest and other income	4,164	3,526
Total revenue	832,935	821,127
Costs and expenses:
Cost of sales	165,367	168,223
Selling, general and administrative	443,863	382,309
Research and development	185,424	195,166
Total costs and expenses	794,654	745,698
Income before income tax expense	38,281	75,429
Income tax expense	15,003	20,144
Net income	$ 23,278	$ 55,285
Net income per share:
Basic (in dollars per share)	$ 0.09	$ 0.21
Diluted (in dollars per share)	$ 0.09	$ 0.21
Weighted average number of common shares outstanding:
Basic (in shares)	267,115	268,389
Diluted (in shares)	268,420	268,972