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Accounting Policies - Inventory (Details 5) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020
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Inventory and natural gas in storage [Line Items] |  |
Aggregates held for resale | $ 184,363 | $ 175,782
Asphalt oil | 57,002 | 28,238
Materials and supplies | 30,629 | 25,142
Merchandise for resale | 28,501 | 21,087
Natural gas in storage (current) | 18,867 | 21,919
Other | 16,247 | 18,999
Total | 335,609 | 291,167
Natural gas in storage (noncurrent) | $ 47,500 | $ 47,500

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- Definition Carrying amount as of the balance sheet date of natural gas in storage, which is a mixture of gases (liquefied or otherwise), used for fuel and manufacturing purposes, which is ready for sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.6(a)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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