Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accrued Liabilities Detail [Table]
Compensation and employee benefits	$ 25,286	$ 20,621
Oil and gas producing liabilities	15,158	9,272
Unearned income	1,561	1,617
Deferred tax liability	15,756	11,763
Contingent consideration, current portion	11,452	0
Other accrued liabilities	20,019	15,205
Accrued liabilities	$ 89,232	$ 58,478