Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Sales	$ 71,396	$ 66,711	$ 158,786	$ 146,368
Cost of sales	46,141	43,232	103,577	95,424
Gross profit	25,255	23,479	55,209	50,944
Operating expenses:
General and administrative	6,200	6,178	13,134	12,404
Advertising	5,300	4,526	12,007	10,818
Depreciation	552	527	1,108	1,058
Total operating expenses	12,052	11,231	26,249	24,280
Income from operations	13,203	12,248	28,960	26,664
Other income:
Interest income, net	428	143	807	226
Other, net	255	249	572	490
Total other income	683	392	1,379	716
Income before provision for income taxes	13,886	12,640	30,339	27,380
Provision for income taxes	3,134	3,880	7,005	9,344
Net income	10,752	8,760	23,334	18,036
Comprehensive income	$ 10,752	$ 8,760	$ 23,334	$ 18,036
Net income per common share:
Basic (in dollars per share)	$ 0.53	$ 0.43	$ 1.14	$ 0.89
Diluted (in dollars per share)	$ 0.52	$ 0.43	$ 1.14	$ 0.88
Weighted average number of common shares outstanding:
Basic (in shares)	20,463	20,349	20,436	20,321
Diluted (in shares)	20,520	20,437	20,485	20,442
Cash dividends declared per common share (in dollars per share)	$ 0.27	$ 0.20	$ 0.52	$ 0.40