Liquidity and Capital Resources (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Estimated projected expenditure [Line Items]
Cash and cash equivalents	$ 28,052,543	$ 32,218,905	$ 62,028,328	$ 11,483,112
Short-term investments	37,101,506	45,621,593
Currently projected expenditures for clinical programs	56,300,000
Aldoxorubicin [Member]
Estimated projected expenditure [Line Items]
Currently projected expenditures for clinical programs	41,700,000
Other Programs [Member]
Estimated projected expenditure [Line Items]
Currently projected expenditures for clinical programs	2,000,000
General Operation [Member]
Estimated projected expenditure [Line Items]
Currently projected expenditures for clinical programs	3,700,000
Other General and Administrative Expenses [Member]
Estimated projected expenditure [Line Items]
Currently projected expenditures for clinical programs	$ 8,900,000