Notes Payable (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2017 USD ($)	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2016 USD ($)
Notes Payable
Current portion of notes payable		$ 3,497		$ 3,497			$ 3,500
Prepayment penalties	$ 0
Interest Expense		$ 72	$ 124	$ 156	$ 248
Credit facility
Notes Payable
Proceeds from the issuance of debt						$ 7,000
Accrued interest rate (as a percent)		6.50%		6.50%
Monthly payments (as a percent)				4.166%
Current portion of notes payable		$ 3,500		$ 3,500
Interest Expense		70		152
Accrued interest		$ 22		$ 22
Number of financial covenants associated with the term loans | item		0		0
Credit facility | Prime rate
Notes Payable
Variable interest rate				prime
Variable rate basis (as a percent)				3.25%