Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities Detail [Table]
Compensation and employee benefits	$ 27,276	$ 20,711
Oil and gas producing liabilities	12,723	14,988
Unearned income	6,988	11,280
Other accrued liabilities	33,983	38,721
Accrued liabilities	$ 80,970	$ 85,700