Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Sales	$ 283,419	$ 273,800	$ 249,176
Cost of sales	188,105	175,993	169,862
Gross profit	95,314	97,807	79,314
Operating expenses:
General and administrative	24,767	24,290	22,799
Advertising	22,148	19,255	17,663
Depreciation	2,225	2,126	1,369
Total operating expenses	49,140	45,671	41,831
Income from operations	46,174	52,136	37,483
Other income (expense):
Interest income, net	1,864	658	141
Other, net	1,083	995	300
Total other income	2,947	1,653	441
Income before provision for income taxes	49,121	53,789	37,924
Provision for income taxes	11,381	16,506	14,105
Net income	37,740	37,283	23,819
Comprehensive income	$ 37,740	$ 37,283	$ 23,819
Net income per common share:
Basic (in dollars per share)	$ 1.84	$ 1.83	$ 1.18
Diluted (in dollars per share)	$ 1.84	$ 1.82	$ 1.17
Weighted average number of common shares outstanding:
Basic (in shares)	20,461	20,346	20,232
Diluted (in shares)	20,491	20,433	20,378
Cash dividends declared per common share (in dollars per share)	$ 1.06	$ 0.85	$ 0.76