Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Trade accounts payable	$ 14,534	$ 13,981
Accrued salaries, vacation and benefits	18,049	17,888
Other accrued expenses	23,379	23,143
Accrued contingent consideration	3,590	2,381
Negative cash book balance	5,044	3,678
Accounts Payable and Accrued Liabilities, Current, Total	$ 64,596	$ 61,071