Stockholders' Equity and Redeemable Convertible Preferred Stock (Details 5) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Total compensation expense	$ 562	$ 371
Restricted Stock Units [Member] | Employee [Member]
Total compensation expense	121
Restricted Stock [Member] | Employee [Member]
Total compensation expense	151	132
Restricted Stock [Member] | Non-Employee [Member]
Total compensation expense	255	84
Stock Option [Member] | Employee [Member]
Total compensation expense	$ 35	$ 155