Basis of Presentation and Summary of Significant Accounting Policies (Details 4) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Provision for U.S. Feraheme sales allowances and accruals
Discounts and chargebacks	$ 10,205,000	$ 6,644,000	$ 26,925,000	$ 19,382,000
Government and other rebates	3,044,000	1,595,000	8,106,000	4,487,000
Medicaid rebate reserve adjustment	(625,000)	(861,000)	(568,000)	(621,000)
Returns	265,000	(1,122,000)	697,000	(1,680,000)
Total provision for U.S. Feraheme sales allowances and accruals	12,889,000	6,256,000	35,160,000	21,568,000
Total gross U.S. Feraheme sales	32,236,000	22,442,000	87,541,000	65,474,000
Total provision for U.S. Feraheme sales allowances and accruals as a percent of total gross U.S. Feraheme sales	40.00%	28.00%	40.00%	33.00%
Product Returns
Current expiration period for packaged products			5 years
Reduction of reserve for product returns				2,100,000
Expiration period for certain manufactured Feraheme lots				2 years
Product returns provision applied to gross sales			700,000	1,700,000
Reduction in Medicaid rebate reserves			$ 600,000	$ 600,000
Reduction in estimated Medicaid rebate reserve, impact per basic and diluted share (in dollars per share)			$ 0.03	$ 0.03