Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Centennial asset impairment charge		$ 0	$ 17,443	$ 0
Revenues	$ 220,792	239,107	572,220	629,341
Operating profit (loss)	699	5,760	11,321	10,289
Net income (loss)	(442)	3,141	5,476	3,893
Operating segments | NACoal
Segment Reporting Information [Line Items]
Revenues	32,402	42,704	85,778	121,965
Operating profit (loss)	(10,912)	(4,010)	3,653	3,579
Net income (loss)	(12,677)	(5,345)	(1,100)	3,401
Operating segments | HBB
Segment Reporting Information [Line Items]
Revenues	157,264	163,291	400,058	416,082
Operating profit (loss)	14,399	11,643	19,162	16,711
Net income (loss)	9,511	6,378	12,184	8,614
Operating segments | KC
Segment Reporting Information [Line Items]
Revenues	32,895	34,708	89,912	94,457
Operating profit (loss)	(921)	(843)	(6,822)	(6,860)
Net income (loss)	(717)	(550)	(4,539)	(4,290)
Operating segments | NACCO and Other
Segment Reporting Information [Line Items]
Operating profit (loss)	(1,867)	(1,142)	(4,605)	(3,267)
Net income (loss)	(1,526)	(774)	(3,711)	(2,710)
Eliminations
Segment Reporting Information [Line Items]
Revenues	(1,769)	(1,596)	(3,528)	(3,163)
Operating profit (loss)	0	112	(67)	126
Net income (loss)	$ 4,967	$ 3,432	$ 2,642	$ (1,122)