Summary of Significant Accounting Policies - Recently Issued Accounting Pronouncements (Details) - USD ($)	Sep. 30, 2017	Jan. 01, 2017	Dec. 31, 2016
Recently Issued Accounting Pronouncements
Additional Paid in Capital	$ 291,841,000		$ 276,127,000
Retained Earnings (Accumulated Deficit)	(40,481,000)		(84,288,000)
Deferred Tax Assets, Net, Noncurrent	$ 28,807,000		$ 41,729,000
ASU 2016-09 | Cumulative Effect Adjustment
Recently Issued Accounting Pronouncements
Additional Paid in Capital		$ 211,000
Retained Earnings (Accumulated Deficit)		(211,000)
ASU 2016-09 | Deferred Tax Asset Adjustment
Recently Issued Accounting Pronouncements
Retained Earnings (Accumulated Deficit)		392,000
Deferred Tax Assets, Net, Noncurrent		$ 392,000