Income Taxes (Reconciliation of the provision for income taxes at the statutory rate to the company's provision for income tax) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
U.S. federal (tax benefit) provision at statutory rate	$ (3,567)	$ 1,197	$ (746)
State (tax benefit) income taxes, net of federal benefit	(338)	151	109
Foreign income taxes at rates other than the US rate	(28)	(10)	(72)
Nondeductible Share-based Compensation Cost	549	397	340
Change in valuation allowance	3,911	(1,494)	546
Non-deductible warrant expense	0	625	334
Research and development credits	527	220	290
Other	109	(19)	64
Total income tax provision	$ 109	$ 627	$ 285
Effective Income Tax Rate, Percent [Abstract]
Effective tax rate	(1.10%)	17.80%	(13.00%)