Consolidated Quarterly Financial Data-Unaudited (Details) (USD $)	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Trading Securities and Other Trading Assets
U.S. Feraheme product sales, net	$ 18,981,000	$ 19,347,000	$ 17,456,000	$ 15,578,000	$ 14,381,000	$ 16,186,000	$ 14,094,000	$ 13,626,000		$ 71,362,000	$ 58,287,000	$ 52,097,000
License fee and other collaboration revenues	2,329,000	1,998,000	2,055,000	2,003,000	6,564,000	1,566,000	16,592,000	1,753,000		8,385,000	26,475,000	8,321,000
Other product sales and royalties	401,000	271,000	138,000	299,000	199,000	(10,000)	326,000	101,000		1,109,000	616,000	831,000
Total revenues	21,711,000	21,616,000	19,649,000	17,880,000	21,144,000	17,742,000	31,012,000	15,480,000		80,856,000	85,378,000	61,249,000
Cost of product sales	3,326,000	2,547,000	3,145,000	2,942,000	4,027,000	4,323,000	3,224,000	2,646,000		11,960,000	14,220,000	10,531,000
Gross margin	18,385,000	19,069,000	16,504,000	14,938,000	17,117,000	13,419,000	27,788,000	12,834,000
Operating expenses	22,380,000	19,464,000	19,260,000	19,409,000	20,532,000	17,420,000	22,772,000	25,643,000
Restructuring expenses					595,000	562,000	1,058,000				2,215,000	3,508,000
Interest and dividend income, net	278,000	246,000	256,000	271,000	260,000	295,000	338,000	393,000		1,051,000	1,286,000	1,747,000
Gains on assets held for sale	59,000		566,000	299,000
(Losses) gains on investments, net	4,000	4,000	26,000	6,000	3,000	2,000	(1,471,000)			40,000	(1,466,000)	(193,000)
Income tax benefit					61,000	299,000	494,000				854,000	1,170,000
Net loss	(3,654,000)	(145,000)	(1,908,000)	(3,895,000)	(3,686,000)	(3,967,000)	3,319,000	(12,416,000)		(9,602,000)	(16,750,000)	(77,069,000)
Net income (loss) per share-basic and diluted (in dollars per share)	$ (0.17)	$ (0.01)	$ (0.09)	$ (0.18)						$ (0.44)	$ (0.78)	$ (3.64)
Net income (loss) per share - basic (in dollars per share)					$ (0.17)	$ (0.19)	$ 0.16	$ (0.58)
Net income (loss) per share - diluted (in dollars per share)					$ (0.17)	$ (0.19)	$ 0.15	$ (0.58)
Reduction in estimated Medicaid rebate reserve related to Feraheme sales		600,000				600,000			2,200,000	(568,000)	(621,000)	(2,532,000)
Milestone payments revenue recognized under the agreement					5,000,000		15,000,000
ARS portfolio
Trading Securities and Other Trading Assets
(Losses) gains on investments, net							$ 1,500,000