Fair Value of Financial Instruments - Earnout Payment Liability (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Earnout Payment Liability [Member]	Dec. 31, 2010 Earnout Payment Liability [Member]	Dec. 31, 2011 Triaccess Technologies [Member] Maximum [Member]	Dec. 31, 2009 Triaccess Technologies [Member] Maximum [Member]
Details of Level 3 fair value measurements
Opening earnout payment liability	$ 1,365	$ 1,509
Accretion	206	323
Change in estimate	(681)	(467)
Ending earnout payment liability	890	1,365
Business Acquisition, Contingent Consideration, at Fair Value, Current			$ 1,000	$ 5,000