Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Accrued Liabilities, Current [Abstract]
Accrued salaries, wages and benefits	$ 4,312	$ 3,604
Accrual for self-insurance liabilities	6,004	5,787
Property taxes	983	584
Sales and Excise Tax Payable, Current	156	481
Other accrued expenses	1,003	959
Total accrued liabilities	$ 12,458	$ 11,415