CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) [Abstract]
Revenues	$ 49,802	$ 37,850	$ 136,074	$ 113,878
Cost of revenues	23,726	17,372	64,026	52,156
Gross profit	26,076	20,478	72,048	61,722
Operating expenses:
Research and development	3,802	2,634	10,348	9,096
Sales and marketing	12,373	9,927	35,647	28,414
General and administrative	2,210	3,280	10,153	11,194
Gain from legal settlement	0	0	(17,250)	0
Total operating expenses	18,385	15,841	38,898	48,704
Income from operations	7,691	4,637	33,150	13,018
Interest and other income (expense), net	293	(91)	318	259
Income before income tax provision	7,984	4,546	33,468	13,277
Income tax provision	2,996	1,696	12,707	4,892
Net income	$ 4,988	$ 2,850	$ 20,761	$ 8,385
Net income per share:
Basic net income per share (in dollars per share)	$ 0.23	$ 0.13	$ 0.95	$ 0.38
Diluted net income per share (in dollars per share)	$ 0.22	$ 0.13	$ 0.93	$ 0.37
Cash dividends declared per share (in dollars per share)	$ 1.00	$ 0	$ 1.00	$ 0
Shares used in the calculation of net income per share:
Weighted average common shares outstanding - basic (in shares)	21,968,000	21,672,000	21,902,000	22,213,000
Weighted average common shares outstanding - diluted (in shares)	22,341,000	21,990,000	22,316,000	22,579,000