Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Components of accrued liabilities
Payroll and vacation	$ 19,240	$ 16,634
Accrued payroll taxes	5,320	2,453
Accrued real estate and personal property taxes	6,531	3,658
Accrued purchase price due to sellers	0	10,895
Sales tax payable	4,889	6,379
Other	14,100	11,037
Total Accrued liabilities	$ 50,080	$ 51,056