CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) [Abstract]
Revenues	$ 42,014	$ 36,003
Cost of revenues	19,165	16,780
Gross profit	22,849	19,223
Operating expenses:
Research and development	2,965	3,454
Sales and marketing	11,769	9,152
General and administrative	3,322	3,419
Total operating expenses	18,056	16,025
Income from operations	4,793	3,198
Interest and other income (expense), net	(230)	294
Income before income tax provision	4,563	3,492
Income tax provision	1,699	1,278
Net income	$ 2,864	$ 2,214
Net income per share:
Basic net income per share (in dollars per share)	$ 0.13	$ 0.10
Diluted net income per share (in dollars per share)	$ 0.13	$ 0.10
Shares used in the calculation of net income per share:
Weighted average common shares outstanding - basic (in shares)	21,817,000	22,681,000
Weighted average common shares outstanding - diluted (in shares)	22,217,000	23,095,000