Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating Loss Carryforwards [Line Items]
Deferred income tax expense (benefit)	$ (308,000)	$ (578,000)	$ (2,967,000)	$ 374,000
Deferred tax liabilities	18,060,000		18,060,000
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Taxable income (loss)	8,334,000	(15,865,000)	(9,346,000)	22,935,000
Current income tax expense (benefit)	0	(318,000)	0	459,000
Operating loss carryforwards	257,700,000		257,700,000
Federal and state research and development tax credits	7,060,000		7,060,000
Operating loss carryforward benefits from stock compensation deductions	54,400,000		54,400,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Current income tax expense (benefit)	(110,000)	$ (27,000)	(323,000)	$ (27,000)
Operating loss carryforwards	$ 120,600,000		$ 120,600,000