Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating Loss Carryforwards [Line Items]
Deferred income tax benefit	$ (881,000)	$ (471,000)	$ (1,519,000)	$ (2,659,000)
Deferred tax liabilities	16,266,000		16,266,000
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Taxable income (loss)	7,950,000	(7,780,000)	19,750,000	(17,680,000)
Current income tax expense (benefit)	159,000	0	395,000	0
Operating loss carryforwards	248,300,000		248,300,000
Operating loss carryforwards acquired in acquisition of business	13,400,000		13,400,000
Federal and state research and development tax credits	7,700,000		7,700,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Current income tax expense (benefit)	(91,000)	$ (120,000)	(222,000)	$ (213,000)
Operating loss carryforwards	$ 137,000,000		$ 137,000,000