Derivative Instruments And Hedging Activities (Effect Of Foreign Exchange Forward Contracts On OCI And Results Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2011		Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	$ 359	[1]	$ (68)	[1]	$ 665	[1]	$ (197)	[1]
Gain (Loss) Reclassified from Accumulated OCI into Income	252	[2]	18	[2]	31	[2]	(415)	[2]
Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing)	(22)	[3]	2	[3]	(133)	[3]	10	[3]
Research And Development [Member] | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	359	[1]	(68)	[1]	665	[1]	(197)	[1]
(Loss) Reclassified from Accumulated OCI into Income	136	[2]	24	[2]	138	[2]	17	[2]
Gain Recognized in Income (Amount Excluded from Effectiveness Testing)	(15)	[3]	3	[3]	(91)	[3]	11	[3]
Sales And Marketing [Member] | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Reclassified from Accumulated OCI into Income	116	[2]
(Loss) Reclassified from Accumulated OCI into Income			(6)	[2]	(107)	[2]	(432)	[2]
(Loss) Recognized in Income (Amount Excluded from Effectiveness Testing)	$ (7)	[1]	$ (1)	[1]	$ (42)	[3]	$ (1)	[3]

[1] The amount represents the change in fair value of derivative contracts due to changes in spot rates.

[2] The amount represents reclassification from other comprehensive income to earnings that occurs when the hedged item affects earnings.

[3] The amount represents the change in fair value of derivative contracts due to changes in the difference between the spot price and forward price that is excluded from the assessment of hedge effectiveness and therefore recognized in earnings. No gains or losses were reclassified as a result of discontinuance of cash flow hedges.