Credit Facilities (Details) (USD $)			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Credit facility Silicon Valley Bank	Dec. 31, 2012 Cash management services sublimit Silicon Valley Bank	Dec. 31, 2012 Letters of credit Silicon Valley Bank	Dec. 31, 2012 Threshold One [Member]	Dec. 31, 2012 Threshold Two [Member]	Dec. 31, 2012 Threshold Three [Member]
Credit Facility [Line Items]
Borrowing capacity			$ 30,000,000	$ 300,000
Customer accounts receivable concentration limit						25.00%	50.00%	85.00%
Minimum net worth requirement			50,000,000
Potential increase in borrowing capacity			20,000,000
Borrowing base requirement			40,000,000
Period for borrowing base requirement			90 days
Cash and cash equivalents, net of amount outstanding under credit agreement			20,000,000
Interest rate over prime			1.00%
Letters of credit outstanding					0
Amount outstanding	2,800,000	0	2,800,000
Available borrowing capacity			$ 16,800,000