Commitments and Contingencies Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 lease	Dec. 31, 2011 lease	Nov. 30, 2010 Silicon Valley Bank [Member]	Oct. 31, 2012 Comerica Bank [Member]	Dec. 31, 2012 Lease 1 [Member]	Dec. 31, 2011 Lease 1 [Member]	Dec. 31, 2012 Lease 2 [Member]	Dec. 31, 2011 Lease 2 [Member]	Dec. 31, 2012 Lease 3 [Member]
Long-term Purchase Commitment [Line Items]
Operating lease payments	$ 547,000	$ 500,000
Number of non-cancelable lease agreements	3	2
Value of non-cancelable capital lease agreements					90,000	512,000	30,000	40,000	48,000
Interest rates on non-cancelable capital lease agreements					9.00%	6.00%	3.00%	0.00%	0.00%
Depreciation expense on the equipment under the capital leases	131,000	51,000
Current portion of capital lease	240,000	177,000
Capital lease, net of current portion	231,000	334,000
Letters of credit outstanding, amount			$ 115,000	$ 115,000