Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current [Abstract]
Federal	$ (354)	$ 12,154	$ 8,036
State	(397)	428	767
Foreign	0	0	9
Current Income Tax Expense (Benefit), Total	(751)	12,582	8,812
Deferred [Abstract]
Federal	0	(40)	(3,331)
State	0	(7)	(1)
Deferred Income Tax Expense (Benefit), Total	0	(47)	(3,332)
Total (benefit) provision for income taxes	(751)	12,535	5,480
Effective Tax Rate Reconciliation [Abstract]
United States federal statutory rate (in hundredths)	35.00%	35.00%	35.00%
State taxes, net of federal benefit (in hundredths)	(1.48%)	1.07%	2.19%
Valuation allowance (in hundredths)	(37.11%)	(4.41%)	(4.39%)
Stock options (in hundredths)	(0.17%)	0.14%	(1.92%)
Prior year true-up (in hundredths)	(1.32%)	1.03%	0.00%
Warrants (in hundredths)	2.10%	(0.82%)	(8.60%)
Other (in hundredths)	0.18%	(0.32%)	1.79%
Balance at the end of the year (in hundredths)	(2.80%)	31.69%	24.07%
Deferred tax assets [Abstract]
Reserves and accruals	58	50	46
State taxes	1	1	1
Research and development credits and other credits	907	0	0
Net operating loss carry forward	8,249	2,254	2,822
Stock based compensation	6,600	4,506	3,155
Other	154	177	211
Total deferred tax assets	15,969	6,988	6,235
Valuation allowance	(15,955)	(6,969)	(6,168)
Deferred tax assets after valuation allowance	14	19	67
Deferred tax liability [Abstract]
Depreciation and amortization	(14)	(19)	(20)
Total deferred tax liabilities	(14)	(19)	(20)
Net deferred tax assets	0	0	47
Net change in valuation allowance	8,986
Federal operating loss carryforwards	23,468
State operating loss carryforwards	37,993
Net change in gross deferred tax assets offset by a change in valuation allowance	316	128	128
Accrued interest and penalties	79
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at the beginning of the year	128	128	128
Additions based on tax positions related to the current year	0	0	0
Additions for tax positions of prior years	188	0	0
Settlements	0	0	0
Lapse of applicable statute of limitations	0	0	0
Balance at the end of the year	$ 316	$ 128	$ 128