Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 25, 2019
Entity Information [Line Items]
Entity Registrant Name	NACCO INDUSTRIES INC
Entity Central Index Key	0000789933
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Shares Outstanding Class A
Entity Information [Line Items]
Shares Outstanding (in shares)		5,425,640
Shares Outstanding Class B
Entity Information [Line Items]
Shares Outstanding (in shares)		1,568,680