Debt - Additional Information (Details) - USD ($)			3 Months Ended		6 Months Ended
	Dec. 23, 2014	Nov. 13, 2014	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Debt outstanding			$ 7,500,000		$ 7,500,000		$ 7,000,000
Borrowings under credit facilities					2,000,000	$ 8,000,000
Repayments of borrowings					1,500,000
Interest expense and fees			200,000	$ 100,000	400,000	$ 200,000
Maximum
Debt Instrument [Line Items]
Accrued interest			$ 100,000		$ 100,000		$ 100,000
$40,000,000 Credit Facilities
Debt Instrument [Line Items]
Debt instrument, face amount	$ 40,000,000
Capex Commitments
Debt Instrument [Line Items]
Debt instrument, face amount		$ 12,000,000
Capex Commitments | $40,000,000 Credit Facilities
Debt Instrument [Line Items]
Debt instrument, face amount	30,000,000
Term Facility
Debt Instrument [Line Items]
Debt instrument, face amount		$ 18,000,000
Credit facility term		5 years
Term Facility | $40,000,000 Credit Facilities
Debt Instrument [Line Items]
Extinguishment amount of debt	18,000,000
Revolving Facility
Debt Instrument [Line Items]
Debt instrument, face amount		$ 10,000,000
Credit facility term		3 years
Increase in credit facility	$ 20,000,000