Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Accrued interest and penalties related to uncertain tax positions	$ 0		$ 0
Deferred tax assets, operating loss carry-forwards	5,384,000		$ 6,871,000	$ 3,989,000
Operating loss carry-forwards, subject to expiration	54,300,000
Scenario, forecast
Operating Loss Carryforwards [Line Items]
Operating loss carry-forwards		$ 6,000,000
Research tax credit carry-forward
Operating Loss Carryforwards [Line Items]
Net operating loss carry-forwards	299,000
Domestic tax authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward utilized	6,200,000
Operating loss carry-forwards	69,100,000
Deferred tax assets, operating loss carry-forwards	$ 14,800,000