Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2012	Jun. 30, 2012	Mar. 01, 2013 Common Class A	Mar. 01, 2013 Common Class B
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
Document Type	10-K
Document Period End Date	Dec. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Amendment Flag	false
Shares Outstanding			6,825,512	1,582,285
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float		$ 674,878,564