Supplemental Oil and Gas Disclosures (Unaudited) (Oil and Natural Gas Properties) (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Extractive Industries [Abstract]
Proved developed	$ 3,266
Proved undeveloped	16,246
Less: accumulated depreciation, depletion and amortization	868
Net royalty interests in oil and natural gas properties	$ 18,644

Proved Developed Oil and Gas Property, Successful Effort Method

No definition available.

Name:	nacco_ProvedDevelopedOilAndGasPropertySuccessfulEffortMethod
Namespace Prefix:	nacco_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Proved Undeveloped Oil and Gas Property, Successful Effort Method

+ References

No definition available.

+ Details

Name:	nacco_ProvedUndevelopedOilAndGasPropertySuccessfulEffortMethod
Namespace Prefix:	nacco_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	srt_ExtractiveIndustriesAbstract
Namespace Prefix:	srt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of accumulated depreciation, depletion, amortization and impairment of oil and gas property carried under the successful effort method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=123377692&loc=d3e61901-109447

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10(b))
-URI http://asc.fasb.org/extlink&oid=123726172&loc=d3e511914-122862

+ Details

Name:	us-gaap_OilAndGasPropertySuccessfulEffortMethodAccumulatedDepreciationDepletionAmortizationAndImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Oil and gas properties net of accumulated depreciation, depletion, amortization, impairment, and abandonment, carried under the successful effort method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=123377692&loc=d3e61901-109447

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10.(b))
-URI http://asc.fasb.org/extlink&oid=123726172&loc=d3e511914-122862

+ Details

Name:	us-gaap_OilAndGasPropertySuccessfulEffortMethodNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant