Change in Accounting Principle (Details) - USD ($)	3 Months Ended	6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2016	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Change in Accounting Principle
Warrant liability		$ 1,500,000			$ 1,900,000
Warrant derivative loss (gain)	$ 545,000	$ (400,000)		$ 2,821,000	(17,100,000)
Warrant liability					922,000
Additional paid in capital			$ 516,237,000		495,455,000
Accumulated Deficit			(507,041,000)		(488,037,000)
ASU 2017-11 Earnings Per Share
Change in Accounting Principle
Warrant derivative loss (gain)			$ 5,000		300,000
Additional paid in capital					514,501,000
Accumulated Deficit					(505,185,000)
Previously Reported
Change in Accounting Principle
Warrant Liability - Related Party					976,000
Warrant liability					922,000
Additional paid in capital					495,455,000
Accumulated Deficit					(488,037,000)
Cumulative Effect Adjustment | ASU 2017-11 Earnings Per Share
Change in Accounting Principle
Warrant Liability - Related Party					(976,000)
Warrant liability					(922,000)
Additional paid in capital					19,046,000
Accumulated Deficit					$ (17,148,000)