CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Sales	$ 234,684	$ 229,395	$ 233,391
Cost of sales	158,388	153,125	155,774
Gross profit	76,296	76,270	77,617
Operating expenses:
General and administrative	21,301	21,101	21,352
Advertising	21,837	25,182	27,180
Discontinued project costs		1,714
Depreciation	770	660	867
Total operating expenses	43,908	48,657	49,399
Income from operations	32,388	27,613	28,218
Other income (expense):
Interest income, net	190	184	185
Realized loss on sale of short term investments	(74)
Other, net	63	1	(4)
Total other income	179	185	181
Income before provision for income taxes	32,567	27,798	28,399
Provision for income taxes	12,000	10,345	10,427
Net income	20,567	17,453	17,972
Net change in unrealized gain (loss) on short term investments	54	(17)	(35)
Comprehensive income	$ 20,621	$ 17,436	$ 17,937
Net income per common share:
Basic	$ 1.02	$ 0.87	$ 0.90
Diluted (in dollars per share)	$ 1.02	$ 0.87	$ 0.90
Weighted average number of common shares outstanding:
Basic (in shares)	20,124	20,015	19,901
Diluted (in shares)	20,254	20,136	20,043
Cash dividends declared per common share (in dollars per share)	$ 0.72	$ 0.68	$ 0.66