Note 9 - Quarterly Results for 2017 and 2018 (Unaudited) - Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	[1]	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net sales	$ 108,413	$ 89,466	$ 92,270	$ 86,552	$ 95,001	$ 95,870	$ 82,392		$ 73,087	$ 376,701	$ 346,350	$ 266,814
Gross profit	34,867	31,451	32,343	30,268	33,744	33,800	29,278		24,875	128,929	121,697	96,352
Income before taxes on income	4,028	4,630	3,652	2,976	5,696	7,282	5,097		3,320
Net income	$ 2,988	$ 3,921	$ 2,781	$ 2,376	$ 4,586	$ 6,122	$ 3,817		$ 2,450	$ 12,066	$ 16,975	$ 15,022
Net income per share:
Basic (in dollars per share)	$ 0.20	$ 0.26	$ 0.19	$ 0.16	$ 0.31	$ 0.41	$ 0.26		$ 0.17	$ 0.81	$ 1.14	$ 1.04
Diluted (in dollars per share)	$ 0.20	$ 0.26	$ 0.18	$ 0.16	$ 0.30	$ 0.39	$ 0.25		$ 0.16	$ 0.79	$ 1.10	$ 0.99
Weighted average number of shares outstanding during the period, basic (in shares)	14,952,963	14,947,552	14,952,802	14,927,341	14,962,603	15,010,660	14,956,221		14,821,659	14,945,165	14,937,786	14,510,156
Weighted average number of shares outstanding during the period, diluted (in shares)	15,248,770	15,266,850	15,287,357	15,262,654	15,371,606	15,499,894	15,559,404		15,457,629	15,266,408	15,472,133	15,118,768
Net sales	$ 108,413	$ 89,466	$ 92,270	$ 86,552	$ 95,001	$ 95,870	$ 82,392		$ 73,087	$ 376,701	$ 346,350	$ 266,814
Gross profit	34,867	31,451	32,343	30,268	33,744	33,800	29,278		24,875	128,929	121,697	96,352
Income before taxes on income	4,028	4,630	3,652	2,976	5,696	7,282	5,097		3,320
Net income	$ 2,988	$ 3,921	$ 2,781	$ 2,376	$ 4,586	$ 6,122	$ 3,817		$ 2,450	$ 12,066	$ 16,975	$ 15,022
Basic (in dollars per share)	$ 0.20	$ 0.26	$ 0.19	$ 0.16	$ 0.31	$ 0.41	$ 0.26		$ 0.17	$ 0.81	$ 1.14	$ 1.04
Diluted (in dollars per share)	$ 0.20	$ 0.26	$ 0.18	$ 0.16	$ 0.30	$ 0.39	$ 0.25		$ 0.16	$ 0.79	$ 1.10	$ 0.99

[1] On May 2, 2018, the Company acquired CID, which manufactures medical uniforms, lab coats, and layers, and sells its products to specialty uniform retailers, ecommerce medical uniform retailers, and other retailers. For further details relating to this acquisition, refer to Note 18.