XML 64 R90.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Jones Day
Related Party Transaction [Line Items]
Legal services	$ 1.0	$ 2.1
Mr. Rankin
Related Party Transaction [Line Items]
Legal services	$ 0.5	$ 0.5

X

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=nacco_JonesDayMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=nacco_AlfredM.RankinJr.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: