Loan and Security Agreement (Details)		1 Months Ended	3 Months Ended	12 Months Ended
	Aug. 04, 2015 USD ($)	May 31, 2014 USD ($) segment	Sep. 30, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Jul. 31, 2014 USD ($)
Loan and Security Agreement
Maximum borrowing limit		$ 30,000,000.0
Loss on retirement of Credit Facility				$ 0	$ (1,572,000)	$ (203,000)
Initial Term Loan member
Loan and Security Agreement
Aggregate principal amount		$ 21,000,000.0
Number of payments of principal and interest payable monthly in arrears | segment		30
Proceeds used to repay existing credit facility		$ 9,300,000
Basis spread (as a percent)		9.85%
First Amendment member
Loan and Security Agreement
Aggregate principal amount							$ 4,000,000.0
First Amendment member | Credit Facility member
Loan and Security Agreement
Amount prepaid for relevant fees and remaining debt owed under the Credit Facility and the First Amendment	$ 26,500,000
Loss on retirement of Credit Facility			$ 1,600,000