Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	9 Months Ended
	Oct. 31, 2011	Sep. 30, 2012
Maximum
Commitment and Contingencies
Estimated term to defend in appeal process		3 years
Ferumoxytol term of data and market exclusitivity even if there is no successful outcome from the appeal process		11 years
Minimum
Commitment and Contingencies
Estimated term to defend in appeal process		2 years
Ferumoxytol term of data and market exclusitivity even if there is no successful outcome from the appeal process		8 years
Merger and reorganization expense
Commitment and Contingencies
Expense reimbursement amount paid in connection with Merger Agreement termination	$ 2.0
Allos Merger Agreement termination fees		$ 12.0