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Inventories and natural gas in storage (Details) - USD ($) $ in Thousands | Jun. 30, 2015 | Dec. 31, 2014 | Jun. 30, 2014
--- | --- | --- | ---
Inventory Disclosure [Abstract] |  |  |
Aggregates held for resale | $ 123,457 | $ 108,161 | $ 112,129
Asphalt oil | 79,422 | 42,135 | 76,525
Materials and supplies | 22,594 | 54,282 | 58,089
Merchandise for resale | 16,140 | 24,420 | 25,507
Refined products | 16,065 | 0 | 0
Natural gas in storage (current) | 11,310 | 19,302 | 10,903
Crude oil | 8,101 | 5,045 | 0
Other | 37,316 | 36,065 | 35,420
Total | 314,405 | 289,410 | 318,573
Natural gas in storage noncurrent | $ 49,300 | $ 49,300 | $ 47,400

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- Definition Aggregated amount of asphalt oil inventory. This amount is net of valuation reserves and adjustments. + References No definition available. + Details
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