Income Taxes (Detail Textuals) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)	$ 816	$ (1,733)	$ 1,839	$ (1,378)
U.S. statutory tax rate			34.00%	34.00%
Reversal of reserve for uncertain tax positions				$ 1,913
Tax benefits from stock-based awards			$ 700	400
Deferred tax assets	$ 1,000		1,000
Equity adjustment to additional paid-in capital			$ 700	$ 400
Federal | Research and development credit carryforwards
Operating Loss Carryforwards [Line Items]
Net federal and state research and development credit carryforwards					$ 5,500
State | Research and development credit carryforwards
Operating Loss Carryforwards [Line Items]
Net federal and state research and development credit carryforwards					$ 100