Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Revenues	$ 21,941	$ 32,402	$ 78,341	$ 85,778
Operating profit (loss)	6,989	(12,779)	26,307	(952)
Operating segments | NACoal
Segment Reporting Information [Line Items]
Revenues	21,941	32,402	78,341	85,778
Operating profit (loss)	8,925	(10,912)	31,127	3,653
Operating segments | NACCO and Other
Segment Reporting Information [Line Items]
Operating profit (loss)	$ (1,936)	$ (1,867)	$ (4,820)	$ (4,605)