XML 39 R1.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Document and Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2019
Feb. 21, 2020
Jun. 30, 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 Filer Category true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Document Type 10-K    
Document Period End Date Dec. 31, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 221,449,254
Shares Outstanding Class A      
Entity Information [Line Items]      
Shares Outstanding (in shares)   5,397,458  
Shares Outstanding Class B      
Entity Information [Line Items]      
Shares Outstanding (in shares)   1,568,670