XML 35 R24.htm IDEA: XBRL DOCUMENT
v3.22.1

Nature of Operations and Basis of Presentation (Narrative) (Details) $ in Thousands, T in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2022 USD ($) operatingSegment | Mar. 31, 2021 USD ($) | Dec. 31, 2021 T
Long-term Purchase Commitment [Line Items] |  |  |
Number of operating segments | operatingSegment | 3 |  |
Expenditures for mineral interests | $ 4,649 | $ 4,876 |
Coal Mining | Falkirk | Long-term Contract with Customer |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Historical lignite coal annual delivery | T |  |  | 0.3
Minerals Management | New Mexico Portion, Permian Basin |  |  |
Long-term Purchase Commitment [Line Items] |  |  |
Expenditures for mineral interests | $ 800 |  |

X
- Definition Energy Related Inventory, Coal, Historical Annual Delivery + References No definition available. + Details
Name: | nacco_EnergyRelatedInventoryCoalHistoricalAnnualDelivery
Namespace Prefix: | nacco_
Data Type: | dtr-types:massItemType
Balance Type: | na
Period Type: | duration

X
- Definition Payments To Acquire Property, Plant, And Equipment And Mineral Rights + References No definition available. + Details
Name: | nacco_PaymentsToAcquirePropertyPlantAndEquipmentAndMineralRights
Namespace Prefix: | nacco_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_LongTermPurchaseCommitmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8672-108599 + Details
Name: | us-gaap_NumberOfOperatingSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=nacco_CoalMiningMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsegmentsAxis=nacco_TheFalkirkMiningCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ContractWithCustomerDurationAxis=us-gaap_LongTermContractWithCustomerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=nacco_MineralsManagementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=nacco_NewMexicoPortionPermianBasinMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |