Stockholders' Equity and Redeemable Convertible Preferred Stock (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Total compensation expense	$ 2	$ 54	$ 13	$ 353
Stock Option [Member]
Total compensation expense	2	54	13	400
Stock Option [Member] | Employee [Member]
Total compensation expense	2	5	13	26
Restricted Stock [Member] | Employee [Member]
Total compensation expense		49		72
Restricted Stock [Member] | Non-Employee [Member]
Total compensation expense				$ 255