Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 284,218	$ 220,792	$ 178,007	$ 173,421	$ 286,519	$ 239,107	$ 196,500	$ 193,734	$ 856,438	$ 915,860	$ 896,782
Gross profit	73,611	51,708	40,529	40,005	63,711	42,215	35,381	38,189	205,853	179,496	185,072
Earnings of unconsolidated mines	14,453	15,102	13,035	12,648	11,569	12,234	12,076	12,553	55,238	48,432	48,396
Operating profit (loss)	30,394	699	5,210	5,412	21,538	5,760	1,288	3,241	41,715	31,827	(66,309)
Net income (loss)	$ 24,131	$ (442)	$ 3,116	$ 2,802	$ 18,091	$ 3,141	$ (275)	$ 1,027	29,607	21,984	(38,118)
Basic earnings (loss) per share:
Basic earnings (loss) per share (USD per share)	$ 3.56	$ (0.07)	$ 0.45	$ 0.41	$ 2.65	$ 0.45	$ (0.04)	$ 0.14
Diluted earnings (loss) per share (USD per share)	$ 3.53	$ (0.07)	$ 0.45	$ 0.41	$ 2.63	$ 0.45	$ (0.04)	$ 0.14
Asset impairment		$ 17,400				$ 7,500
NACoal
Segment Reporting Information [Line Items]
Legal matter resolution charge	$ 3,300
Operating Segments | NACoal
Segment Reporting Information [Line Items]
Revenues	25,303	32,402	$ 23,089	$ 30,287	$ 26,033	42,704	$ 37,942	$ 41,319	111,081	147,998	172,702
Gross profit									12,341	(10,816)	(3,139)
Operating profit (loss)	1,966	(10,912)	4,823	9,742	(3,058)	(4,010)	2,382	5,207	5,619	521	(89,030)
Net income (loss)	9,344	(12,677)	3,324	8,253	2,218	(5,345)	4,199	4,547	8,244	5,619	(50,977)
Operating Segments | HBB
Segment Reporting Information [Line Items]
Revenues	205,112	157,264	127,054	115,740	204,895	163,291	129,498	123,293	605,170	620,977	559,683
Gross profit									128,414	123,139	117,570
Operating profit (loss)	23,871	14,399	4,696	67	18,090	11,643	2,880	2,188	43,033	34,801	35,772
Net income (loss)	14,373	9,511	2,934	(261)	11,135	6,378	1,618	618	26,557	19,749	23,144
Operating Segments | KC
Segment Reporting Information [Line Items]
Revenues	54,439	32,895	28,634	28,383	56,531	34,708	29,782	29,967	144,351	150,988	168,545
Gross profit									65,391	67,000	71,621
Operating profit (loss)	7,198	(921)	(3,011)	(2,890)	7,025	(843)	(2,972)	(3,045)	376	165	(7,075)
Net income (loss)	4,184	(717)	(1,954)	(1,868)	3,870	(550)	(1,847)	(1,893)	(355)	(420)	(4,603)
Eliminations
Segment Reporting Information [Line Items]
Revenues	(636)	(1,769)	(770)	(989)	(940)	(1,596)	(722)	(845)	(4,164)	(4,103)	(4,148)
Gross profit									(34)	589	(519)
Operating profit (loss)	32	0	(1)	(66)					(35)	588	(520)
Net income (loss)	(2,665)	4,967	(70)	(2,255)	1,504	3,432	(3,548)	(1,006)	(23)	382	(338)
Eliminations | NACCO and Other
Segment Reporting Information [Line Items]
Operating profit (loss)					462	112	(166)	180
NACCO and Other | NACCO and Other
Segment Reporting Information [Line Items]
Gross profit									(259)	(416)	(461)
Operating profit (loss)	(2,673)	(1,867)	(1,297)	(1,441)	(981)	(1,142)	(836)	(1,289)	(7,278)	(4,248)	(5,456)
Net income (loss)	$ (1,105)	$ (1,526)	$ (1,118)	$ (1,067)	$ (636)	$ (774)	$ (697)	$ (1,239)	$ (4,816)	$ (3,346)	$ (5,344)