Nature of Operations and Basis of Presentation	3 Months Ended
Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	Nature of Operations and Basis of Presentation Nature of Operations: The accompanying Unaudited Condensed Consolidated Financial Statements include the accounts of NACCO Industries, Inc. (the “parent company” or “NACCO”) and its wholly owned subsidiaries (collectively, “NACCO Industries, Inc. and Subsidiaries” or the “Company”). Intercompany accounts and transactions are eliminated in consolidation. NACCO is the public holding company for The North American Coal Corporation. The North American Coal Corporation and its affiliated companies (collectively, “NACoal”) operate surface mines that supply coal primarily to power generation companies under long-term contracts, and provide other value-added services to natural resource companies. In addition, its North American Mining ("NAM") business operates and maintains draglines and other equipment under contracts with sellers of aggregates. On September 29, 2017, the Company spun-off Hamilton Beach Brands Holding Company ("HBBHC"), a former wholly owned subsidiary. The financial position, results of operations and cash flows of HBBHC are reflected as discontinued operations for all periods presented through the date of the spin-off. See Note 10 to the Unaudited Condensed Consolidated Financial Statements for further details regarding the spin-off. NACoal has the following operating coal mining subsidiaries: Bisti Fuels Company, LLC ("Bisti"), Caddo Creek Resources Company, LLC (“Caddo Creek”), Camino Real Fuels, LLC (“Camino Real”), The Coteau Properties Company (“Coteau”), Coyote Creek Mining Company, LLC (“Coyote Creek”), Demery Resources Company, LLC (“Demery”), The Falkirk Mining Company (“Falkirk”), Mississippi Lignite Mining Company (“MLMC”) and The Sabine Mining Company (“Sabine”). Liberty Fuels Company, LLC ("Liberty") ceased all mining and delivery of lignite in 2017 and commenced mine reclamation in 2018. All of the operating coal mining subsidiaries other than MLMC are unconsolidated (collectively, the "Unconsolidated Operations"). The unconsolidated coal mining subsidiaries were formed to develop, construct and/or operate surface coal mines under long-term contracts and are capitalized primarily with debt financing provided by or supported by their respective customers, and without recourse to NACCO and NACoal. Although NACoal owns 100% of the equity and manages the daily operations of the Unconsolidated Operations, the Company has determined that the equity capital provided by NACoal is not sufficient to adequately finance the ongoing activities or absorb any expected losses without additional support from the customers. The customers have a controlling financial interest and have the power to direct the activities that most significantly affect the economic performance of the entities. As a result, NACoal is not the primary beneficiary and therefore does not consolidate these entities' financial positions or results of operations. The income taxes resulting from operations of the Unconsolidated Operations are solely the responsibility of the Company. The pre-tax income from the Unconsolidated Operations is reported on the line “Earnings of unconsolidated operations” in the Consolidated Statements of Operations, with related taxes included in the provision for income taxes. The Company has included the pre-tax earnings of the Unconsolidated Operations above operating profit as they are an integral component of the Company's business and operating results. The contracts with the customers of the unconsolidated subsidiaries eliminate exposure to spot coal market price fluctuations and are based on a "management fee" approach, whereby compensation includes reimbursement of all operating costs, plus a fee based on the amount of coal or limestone delivered. The fees earned adjust over time in line with various indices which reflect general U.S. inflation rates. MLMC is a consolidated entity because NACoal pays all operating costs and provides the capital for the mine. MLMC sells coal to its customer at a contractually agreed upon price which adjusts monthly, primarily based on changes in the level of established indices which reflect general U.S. inflation rates. Centennial Natural Resources, LLC ("Centennial"), which ceased coal production at the end of 2015, is also a consolidated entity. NAM provides value-added services for independently owned limestone quarries and is reimbursed by its customers based on actual costs plus a management fee per unit of limestone delivered. The financial results for NAM are included in the consolidated operations or Unconsolidated Operations based on each entity's structure. NACoal also provides coal handling, processing and drying services for a number of customers. For example, NoDak Energy Services, LLC ("NoDak") operates and maintains a coal processing facility for a customer's power plant. The pre-tax income from NoDak is reported on the line "Income from other unconsolidated affiliates" in the "Other expense (income)" section of the Consolidated Statements of Operations, with the related income taxes included in the provision for income taxes. North American Coal Royalty Company, a consolidated entity, provides surface and mineral acquisition and lease maintenance services related to the Company's operations. All of the unconsolidated subsidiaries are accounted for under the equity method. See Note 6 for further discussion. Basis of Presentation: These financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the financial position of the Company at March 31, 2018 and the results of its operations, comprehensive income (loss), cash flows and changes in equity for the three months ended March 31, 2018 and 2017 have been included. These Unaudited Condensed Consolidated Financial Statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2017. The balance sheet at December 31, 2017 has been derived from the audited financial statements at that date but does not include all of the information or notes required by U.S. GAAP for complete financial statements. Reclassifications: As a result of the reclassification of HBBHC to discontinued operations and the adoption of new accounting standards, certain amounts in the prior period Unaudited Condensed Consolidated Financial Statements have been reclassified to conform to the current period's presentation.

Nature of Operations and Basis of Presentation

Nature of Operations: The accompanying Unaudited Condensed Consolidated Financial Statements include the accounts of NACCO Industries, Inc. (the “parent company” or “NACCO”) and its wholly owned subsidiaries (collectively, “NACCO Industries, Inc. and Subsidiaries” or the “Company”). Intercompany accounts and transactions are eliminated in consolidation. NACCO is the public holding company for The North American Coal Corporation. The North American Coal Corporation and its affiliated companies (collectively, “NACoal”) operate surface mines that supply coal primarily to power generation companies under long-term contracts, and provide other value-added services to natural resource companies. In addition, its North American Mining ("NAM") business operates and maintains draglines and other equipment under contracts with sellers of aggregates.

On September 29, 2017, the Company spun-off Hamilton Beach Brands Holding Company ("HBBHC"), a former wholly owned subsidiary. The financial position, results of operations and cash flows of HBBHC are reflected as discontinued operations for all periods presented through the date of the spin-off. See Note 10 to the Unaudited Condensed Consolidated Financial Statements for further details regarding the spin-off.

NACoal has the following operating coal mining subsidiaries: Bisti Fuels Company, LLC ("Bisti"), Caddo Creek Resources Company, LLC (“Caddo Creek”), Camino Real Fuels, LLC (“Camino Real”), The Coteau Properties Company (“Coteau”), Coyote Creek Mining Company, LLC (“Coyote Creek”), Demery Resources Company, LLC (“Demery”), The Falkirk Mining Company (“Falkirk”), Mississippi Lignite Mining Company (“MLMC”) and The Sabine Mining Company (“Sabine”). Liberty Fuels Company, LLC ("Liberty") ceased all mining and delivery of lignite in 2017 and commenced mine reclamation in 2018.

All of the operating coal mining subsidiaries other than MLMC are unconsolidated (collectively, the "Unconsolidated Operations"). The unconsolidated coal mining subsidiaries were formed to develop, construct and/or operate surface coal mines under long-term contracts and are capitalized primarily with debt financing provided by or supported by their respective customers, and without recourse to NACCO and NACoal. Although NACoal owns 100% of the equity and manages the daily operations of the Unconsolidated Operations, the Company has determined that the equity capital provided by NACoal is not sufficient to adequately finance the ongoing activities or absorb any expected losses without additional support from the customers. The customers have a controlling financial interest and have the power to direct the activities that most significantly affect the economic performance of the entities. As a result, NACoal is not the primary beneficiary and therefore does not consolidate these entities' financial positions or results of operations. The income taxes resulting from operations of the Unconsolidated Operations are solely the responsibility of the Company. The pre-tax income from the Unconsolidated Operations is reported on the line “Earnings of unconsolidated operations” in the Consolidated Statements of Operations, with related taxes included in the provision for income taxes. The Company has included the pre-tax earnings of the Unconsolidated Operations above operating profit as they are an integral component of the Company's business and operating results.

The contracts with the customers of the unconsolidated subsidiaries eliminate exposure to spot coal market price fluctuations and are based on a "management fee" approach, whereby compensation includes reimbursement of all operating costs, plus a fee based on the amount of coal or limestone delivered. The fees earned adjust over time in line with various indices which reflect general U.S. inflation rates.

MLMC is a consolidated entity because NACoal pays all operating costs and provides the capital for the mine. MLMC sells coal to its customer at a contractually agreed upon price which adjusts monthly, primarily based on changes in the level of established indices which reflect general U.S. inflation rates. Centennial Natural Resources, LLC ("Centennial"), which ceased coal production at the end of 2015, is also a consolidated entity.

NAM provides value-added services for independently owned limestone quarries and is reimbursed by its customers based on actual costs plus a management fee per unit of limestone delivered. The financial results for NAM are included in the consolidated operations or Unconsolidated Operations based on each entity's structure.

NACoal also provides coal handling, processing and drying services for a number of customers. For example, NoDak Energy Services, LLC ("NoDak") operates and maintains a coal processing facility for a customer's power plant. The pre-tax income from NoDak is reported on the line "Income from other unconsolidated affiliates" in the "Other expense (income)" section of the Consolidated Statements of Operations, with the related income taxes included in the provision for income taxes. North American Coal Royalty Company, a consolidated entity, provides surface and mineral acquisition and lease maintenance services related to the Company's operations.

All of the unconsolidated subsidiaries are accounted for under the equity method. See Note 6 for further discussion.

Basis of Presentation: These financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation of the financial position of the Company at March 31, 2018 and the results of its operations, comprehensive income (loss), cash flows and changes in equity for the three months ended March 31, 2018 and 2017 have been included. These Unaudited Condensed Consolidated Financial Statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2017.

The balance sheet at December 31, 2017 has been derived from the audited financial statements at that date but does not include all of the information or notes required by U.S. GAAP for complete financial statements.

Reclassifications: As a result of the reclassification of HBBHC to discontinued operations and the adoption of new accounting standards, certain amounts in the prior period Unaudited Condensed Consolidated Financial Statements have been reclassified to conform to the current period's presentation.