Business Combinations and Asset Acquisitions (Details) (USD $)	3 Months Ended		6 Months Ended					6 Months Ended		0 Months Ended	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Zerusa Limited [Member]	Sep. 02, 2011 Zerusa Limited [Member]	Jan. 27, 2011 Zerusa Limited [Member]	Jun. 30, 2012 Accumed Systems, Inc. [Member]	Jun. 11, 2012 Accumed Systems, Inc. [Member]	Jan. 06, 2012 Dr. Pedro Silva and Affiliates [Member]	Dec. 22, 2011 Northeast Scientific [Member]
Purchase price allocation [Abstract]
Business acquisition, cost of acquired entity, purchase price, total							$ 4,272,000		$ 1,500,000
Acquired Indefinite-lived Intangible Asset, Amount										3,250,000	900,000
Business acquisition, cost of acquired entity, cash paid						390,000	3,882,000		1,500,000
Business acquisition, purchase price allocation, liabilities assumed							0		0
Purchase price asset allocation [Abstract]
Inventory and equipment					48,000			8,000
Purchased technology					1,000,000			740,000
Other intangibles					800,000			190,000
Goodwill					2,424,000			562,000
Total asset purchase price allocation					4,272,000			1,500,000
Estimated useful life of purchased technology and other intangible assets, minimum (in years)								9Y
Estimated useful life of purchased technology and other intangible assets, maximum (in years)								10Y
Estimated useful life of purchased technology and other intangible assets (in years)					11Y					10Y	5Y
Business acquisition, pro forma information [Abstract]
Revenue	24,830,000	22,349,000	48,717,000	43,758,000
Net earnings	$ 2,360,000	$ 2,114,000	$ 4,247,000	$ 3,755,000
Net earnings per share [Abstract]
Net earnings per share Basic (in dollar per share)	$ 0.15	$ 0.13	$ 0.27	$ 0.23
Net earnings per share Diluted (in dollar per share)	$ 0.15	$ 0.12	$ 0.26	$ 0.22