Summary of Significant Accounting Policies Summary of Significant Accounting Policies Useful Life (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Asset Impairment Charges	$ 0	$ 0	$ 0
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	6 years	3 years
Computer Equipment And Software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years	3 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years	3 years