v2.4.0.6

Inventory (Details) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2012 | Dec. 31, 2011
--- | --- | ---
Inventory |  |
Parts and other consumables | $ 8,559 | $ 11,884
Fuel | 8,296 | 6,744
Total inventory | $ 16,855 | $ 18,628

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