Income Taxes (Net Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Abstract]
Net operating loss carryforward	$ 112,289	$ 171,074
Foreign tax credit carryforward (LT)	631	315
Capitalized research and development	66,500	78,147
Share-based compensation	18,735	22,233
Loss on equity investment	6,294	5,900
Organization costs	30	46
Depreciation	772	1,050
Intangibles	30,788	47,595
Inventory reserve and other	2,145	3,631
Total deferred tax assets	238,184	329,991
Goodwill	(939)	(1,376)
Total deferred tax liability	(939)	(1,376)
Total deferred tax assets, net	237,245	328,615
Valuation allowance	(238,184)	(329,991)
Deferred tax liability	$ (939)	$ (1,376)