Income Taxes (Schedule Of Differences Between Statutory Tax Rate And Effective Tax Rate) (Details)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Income Tax Expense Reconciliation [Line Items]
Statutory federal tax expense (benefit) rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	(242.90%)	(5.00%)	(33.50%)
Differences between statutory rate and foreign effective tax rate	(142.90%)	(15.20%)	(33.50%)
Valuation allowance	936.50%	35.00%	(195.10%)
Research and development credits	(128.60%)	(8.60%)	(39.20%)
Non-deductible acquisition-related costs and tax expense from integration restructurings		0.00%	16.70%
Differences between book and tax loss on strategic investments	0.00%	(15.20%)	0.00%
Effective Income Tax Rate Reconciliation, Tax Settlement, Percent	(657.10%)	0.00%	0.00%
Expiration of statutes of limitations		0.00%	(266.80%)
Non-deductible stock-based compensation	385.70%	21.50%	205.60%
Acquisition-related contingent consideration	(185.70%)	(16.50%)
Other	(14.30%)	(1.50%)	(11.40%)
Effective tax benefit rate	(14.30%)	29.50%	(322.20%)