Fair Value Measurements Rollforward (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2016		$ 893,000
Change in fair value of warrant liability	$ (15,000)	52,000
Balance at September 30, 2017	945,000	945,000
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2016		893,000
Change in fair value of warrant liability		52,000
Balance at September 30, 2017	$ 945,000	$ 945,000