Income Taxes (Detail Textuals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards for federal	$ 16,013
Net operating loss carryforwards for California	6,861
Income penalties expense	0	$ 0
Federal research and development
Tax Credit Carryforward [Line Items]
Federal research and development credit carryforwards	$ 98