Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Sales	$ 60,068	$ 60,110	$ 218,854	$ 206,478
Cost of sales	40,687	38,166	144,264	133,590
Gross profit	19,381	21,944	74,590	72,888
Operating expenses:
General and administrative	5,793	5,818	18,927	18,222
Advertising	3,619	4,126	15,626	14,944
Depreciation	556	532	1,664	1,590
Total operating expenses	9,968	10,476	36,217	34,756
Income from operations	9,413	11,468	38,373	38,132
Other income:
Interest income, net	508	191	1,315	417
Other, net	255	265	827	755
Total other income	763	456	2,142	1,172
Income before provision for income taxes	10,176	11,924	40,515	39,304
Provision for income taxes	2,389	2,860	9,394	12,204
Net income	7,787	9,064	31,121	27,100
Comprehensive income	$ 7,787	$ 9,064	$ 31,121	$ 27,100
Net income per common share:
Basic (in dollars per share)	$ 0.38	$ 0.45	$ 1.52	$ 1.33
Diluted (in dollars per share)	$ 0.38	$ 0.44	$ 1.52	$ 1.33
Weighted average number of common shares outstanding:
Basic (in shares)	20,483	20,368	20,452	20,337
Diluted (in shares)	20,493	20,425	20,487	20,437
Cash dividends declared per common share (in dollars per share)	$ 0.27	$ 0.20	$ 0.79	$ 0.60