Debt (Details) (USD $)	3 Months Ended		9 Months Ended					9 Months Ended					9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2012 GE Credit Agreement [Member]	Dec. 31, 2011 GE Credit Agreement [Member]	Sep. 30, 2012 Minimum [Member] GE Credit Agreement [Member]	Sep. 30, 2012 Minimum [Member] LIBOR Rate [Member] GE Credit Agreement [Member]	Sep. 30, 2012 Minimum [Member] Base Rate [Member] GE Credit Agreement [Member]	Oct. 28, 2011 Non-Amended [Member] GE Credit Agreement [Member]	Oct. 28, 2011 Amended [Member] GE Credit Agreement [Member]	Sep. 30, 2012 Letter Of Credit [Member]	Sep. 30, 2012 Tenaxis, Inc. [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, aggregate amount											$ 15,000,000	$ 20,000,000
Letter of credit relating to patent infringement legal proceeding													157,000
Letter of credit, initial term														1 year
Letter of credit, period of additional renewal terms														1 year
Revolving credit facility, restriction on cash and cash equivalents	5,000,000		5,000,000		5,000,000			5,000,000
Revolving credit facility, liquidity requirement after effect to stock repurchase								20,000,000
Interest rate on amounts borrowed									4.25%	3.25%
Revolving credit facility, outstanding balance						0	0
Revolving credit facility, aggregate interest rate						6.50%	6.50%
Revolving credit facility, remaining availability						19,800,000	19,800,000
Total interest expense	$ 42,000	$ 49,000	$ 159,000	$ 116,000