Selected Quarterly Financial Information (Details) (USD $)	3 Months Ended													12 Months Ended
	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, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
REVENUE	$ 37,151,000	$ 37,069,000	$ 34,690,000	$ 35,731,000	$ 35,457,000		$ 36,250,000	$ 33,520,000	$ 35,536,000	$ 32,800,000	$ 33,429,000	$ 33,188,000	$ 32,301,000	$ 144,641,000	$ 140,763,000	$ 131,718,000
GROSS MARGIN	22,635,000	23,799,000	22,384,000	22,473,000	22,282,000		23,349,000	21,479,000	23,276,000	21,045,000	21,310,000	21,371,000	21,292,000	91,291,000	90,386,000	85,018,000
NET INCOME	1,776,000	2,326,000	2,161,000	1,059,000	9,026,000		3,169,000	1,785,000	2,192,000	2,083,000	1,538,000	3,334,000	991,000	7,322,000	16,172,000	7,946,000
INCOME (LOSS) PER COMMON SHARE - DILUTED	$ 0.06	$ 0.08	$ 0.08	$ 0.04	$ 0.31	[1]	$ 0.11	$ 0.06	$ 0.08	$ 0.07	$ 0.06	$ 0.12	$ 0.04	$ 0.25	$ 0.57	$ 0.28
Gain on sale of Medafor investment														530,000	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.’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.