Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 19, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-9172
Entity Registrant Name	NACCO INDUSTRIES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	34-1505819
Entity Address, Address Line One	5875 Landerbrook Drive,
Entity Address, Address Line Two	Suite 220
Entity Address, City or Town	Cleveland,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	44124-4069
City Area Code	440
Local Phone Number	229-5151
Title of 12(b) Security	Class A Common Stock, $1 par value per share
Trading Symbol	NC
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 96,645,091
Documents Incorporated by Reference	Portions of the Company's Proxy Statement for its 2021 annual meeting of stockholders are incorporated herein by reference in Part III of this Form 10-K.
Entity Central Index Key	0000789933
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Shares Outstanding Class A
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		5,490,948
Shares Outstanding Class B
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		1,566,877