Accrued Expenses and Other Current Liabilities - Tabular Disclosure (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Accrued Expenses
Salaries	$ 3,912	$ 4,566
Accrued vacation	4,868	4,672
Accrued incentive compensation	9,338	13,403
Other employee benefits	1,410	1,305
Professional fees	2,708	1,261
Accrued interest	873	873
Workforce reduction charges	2,310
Other	12,410	12,157
Total accrued expenses and other current liabilities	$ 37,829	$ 38,237