CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) [Abstract]
Revenues	$ 52,876	$ 56,051	$ 161,941	$ 150,576
Cost of revenues	23,274	27,268	70,985	70,014
Gross profit	29,602	28,783	90,956	80,562
Operating expenses:
Research and development	4,428	3,585	13,840	11,764
Sales and marketing	10,395	10,742	31,766	30,193
General and administrative	3,524	4,770	11,301	11,475
Total operating expenses	18,347	19,097	56,907	53,432
Income from operations	11,255	9,686	34,049	27,130
Interest and other income (expense), net	231	(197)	716	(595)
Income from continuing operations before income tax provision	11,486	9,489	34,765	26,535
Income tax provision	3,532	3,274	11,993	9,534
Income from continuing operations	7,954	6,215	22,772	17,001
Discontinued operations (Note 4)
Income (loss) from discontinued operations, net of tax	4	(330)	(3)	(1,001)
Net income	$ 7,958	$ 5,885	$ 22,769	$ 16,000
Basic
Continuing operations (in dollars per share)	$ 0.35	$ 0.27	$ 1.00	$ 0.75
Discontinued operations (in dollars per share)	0	(0.01)	0	(0.04)
Basic net income per share (in dollars per share)	0.35	0.26	1.00	0.71
Diluted
Continuing operations (in dollars per share)	0.35	0.27	1.00	0.75
Discontinued operations (in dollars per share)	0	(0.01)	0	(0.05)
Diluted net income per share (in dollars per share)	$ 0.35	$ 0.26	$ 1.00	$ 0.70
Shares used in the calculation of net income per share:
Weighted average common shares outstanding - basic (in shares)	22,725,000	22,533,000	22,684,000	22,483,000
Weighted average common shares outstanding - diluted (in shares)	22,889,000	22,756,000	22,884,000	22,717,000
Cash dividends declared per share (in dollars per share)	$ 0.11	$ 0.10	$ 0.33	$ 0.30