Selected Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended													12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
REVENUE	$ 39,838	$ 36,703	$ 35,526	$ 33,831	$ 37,151	$ 37,069	$ 34,690	$ 35,731	$ 35,457		$ 36,250	$ 33,520	$ 35,536	$ 145,898	$ 144,641	$ 140,763
GROSS MARGIN	26,516	22,982	21,554	19,667	22,635	23,799	22,384	22,473	22,282		23,349	21,479	23,276	90,719	91,291	90,386
NET (LOSS) INCOME	$ 2,636	$ 2,145	$ (502)	$ (274)	$ 1,776	$ 2,326	$ 2,161	$ 1,059	$ 9,026	[1]	$ 3,169	$ 1,785	$ 2,192	$ 4,005	$ 7,322	$ 16,172
(LOSS) INCOME PER COMMON SHARE	$ 0.09	$ 0.07	$ (0.02)	$ (0.01)	$ 0.06	$ 0.08	$ 0.08	$ 0.04	$ 0.31	[1]	$ 0.11	$ 0.06	$ 0.08	$ 0.14	$ 0.25	$ 0.57
Gain on sale of Medafor investment														$ 891	$ 530	$ 12,742
Other than temporary investment impairment																$ 3,229
Medafor Inc. [Member]
Business Acquisition [Line Items]
Gain on sale of Medafor investment									$ 12,700
Series A Junior Participating Preferred Stock [Member] | ValveXchange, Inc. [Member]
Business Acquisition [Line Items]
Other than temporary investment impairment									$ 3,200

[1] The fourth quarter 2013 net income and income per common share-diluted includes the favorable effect of a $12.7 million pre-tax gain on the sale of an investment in the common stock of Medafor, Inc. as a result of C.R. Bard, Inc.'s acquisition of the outstanding common shares of Medafor, Inc. and the unfavorable effect of a $3.2 million other than temporary investment impairment as a result of the impairment and write-down of the Company's investment in ValveXchange preferred stock.