Leadership Changes and Restructuring Activities (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2014
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Equity-based compensation expense	$ 868,000	$ 501,000	$ 2,161,000	$ 1,812,000
Former Chief Financial Officer and Chief Operating Officer | Separation And Transition Agreement | Selling, General and Administrative Expenses [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Severance and other related expenses			$ 0	1,043,000
Equity-based compensation expense				$ 331,000
Former Chief Executive Officer | Separation Agreement
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Severance period					36 months
Former Chief Executive Officer | Separation Agreement | Selling, General and Administrative Expenses [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Equity-based compensation expense					$ 1,007,000
Severance liability					$ 3,581,000