CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) [Abstract]
Revenues	$ 45,851	$ 44,258	$ 89,020	$ 86,272
Cost of revenues	23,979	21,135	46,256	40,300
Gross profit	21,872	23,123	42,764	45,972
Operating expenses:
Research and development	3,418	3,581	6,591	6,546
Sales and marketing	9,902	11,505	19,930	23,274
General and administrative	2,853	4,621	5,908	7,943
Gain from legal settlement	0	(17,250)	0	(17,250)
Total operating expenses	16,173	2,457	32,429	20,513
Income from operations	5,699	20,666	10,335	25,459
Interest and other income (expense), net	507	255	911	25
Income before income tax provision	6,206	20,921	11,246	25,484
Income tax provision	2,210	8,012	4,021	9,711
Net income	$ 3,996	$ 12,909	$ 7,225	$ 15,773
Net income per share:
Basic net income per share (in dollars per share)	$ 0.18	$ 0.59	$ 0.32	$ 0.72
Diluted net income per share (in dollars per share)	$ 0.18	$ 0.58	$ 0.32	$ 0.71
Shares used in the calculation of net income per share:
Weighted average common shares outstanding - basic (in shares)	22,306,000	21,920,000	22,268,000	21,869,000
Weighted average common shares outstanding - diluted (in shares)	22,574,000	22,306,000	22,589,000	22,280,000