Selected Quarterly Financial Information (Details) (USD $)	3 Months Ended													12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business Acquisition [Line Items]
REVENUE	$ 35,457,000		$ 36,250,000	$ 33,520,000	$ 35,536,000	$ 32,800,000	$ 33,429,000	$ 33,188,000	$ 32,301,000	$ 30,397,000	$ 29,654,000	$ 29,379,000	$ 30,196,000	$ 140,763,000	$ 131,718,000	$ 119,626,000
GROSS MARGIN	22,282,000		23,349,000	21,479,000	23,276,000	21,045,000	21,310,000	21,371,000	21,292,000	19,375,000	18,912,000	19,053,000	18,504,000	90,386,000	85,018,000	75,844,000
NET INCOME	9,026,000	[1]	3,169,000	1,785,000	2,192,000	2,083,000	1,538,000	3,334,000	991,000	1,866,000	2,019,000	1,820,000	1,666,000	16,172,000	7,946,000	7,371,000
INCOME (LOSS) PER COMMON SHARE - DILUTED	$ 0.31	[1]	$ 0.11	$ 0.06	$ 0.08	$ 0.07	$ 0.06	$ 0.12	$ 0.04	$ 0.07	$ 0.07	$ 0.06	$ 0.06	$ 0.57	$ 0.28	$ 0.26
Gain on sale of Medafor investment	12,700,000													12,742,000
Other than temporary investment impairment														3,229,000	340,000
Medafor Inc. [Member]
Business Acquisition [Line Items]
Gain on sale of Medafor investment	12,700,000
Series A Preferred Stock [Member] | ValveXchange, Inc. [Member]
Business Acquisition [Line Items]
Other than temporary investment impairment	$ 3,200,000

[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. completing its 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.