Nature of Business (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Nature of Business
Deferred revenue recognized from the terminated Telles joint venture		$ 38,885,000
Unrestricted cash, cash equivalents and investments	19,209,000
Period over which company's present capital resources are not sufficient to fund its planned operations	12 months
Minimum
Significant additional funding
Expected fund to be raised for additional financing to continue operations	50,000,000
Period over which expected fund to be raised	12 months
Maximum
Significant additional funding
Expected fund to be raised for additional financing to continue operations	$ 60,000,000
Period over which expected fund to be raised	15 months