Commitments and Contingencies (Details)	3 Months Ended
	Mar. 31, 2013
Maximum
Legal Proceedings
Estimated term to defend the validity of patent through the appeals process	3 years
Ferumoxytol term of data and market exclusivity even if there is no successful outcome from the appeals process	10 years
Minimum
Legal Proceedings
Estimated term to defend the validity of patent through the appeals process	2 years
Ferumoxytol term of data and market exclusivity even if there is no successful outcome from the appeals process	8 years