Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Summary of segment information
Total assets	$ 304,762		$ 304,762		$ 258,029
Net revenues from external customers	18,418	$ 10,608	33,020	$ 26,566
Depreciation and amortization expense	635	669	1,296	1,337
Operating (loss) income	4,365	1,358	7,715	6,458
Interest expense, net	(2,969)	(181)	(5,945)	(429)
Income tax (expense) benefit	(265)	47	(279)	(6)
Operating Segments | Ligand
Summary of segment information
Total assets	239,133		239,133		184,215
Net revenues from external customers	5,200	5,692	14,206	12,483
Depreciation and amortization expense	38	68	102	134
Operating (loss) income	(4,465)	(867)	(4,007)	(938)
Interest expense, net	(2,969)	(181)	(5,945)	(429)
Income tax (expense) benefit	(254)	45	(268)	(6)
Operating Segments | CyDex
Summary of segment information
Total assets	65,629		65,629		$ 73,814
Net revenues from external customers	13,218	4,916	18,814	14,083
Depreciation and amortization expense	597	601	1,194	1,203
Operating (loss) income	8,830	2,225	11,722	7,396
Interest expense, net			0	0
Income tax (expense) benefit	$ (11)	$ 2	$ (11)	$ 0