Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segment Reporting Information [Line Items]
Revenues	$ 221,714		$ 228,614		$ 599,497		$ 620,683
Operating profit (loss)	11,323		16,682		6,847		32,507
Net income (loss)	7,699		12,325		2,551		21,894
Selling, general and administrative expenses	46,373		43,269		145,792		142,054
Operating segments | NACoal
Segment Reporting Information [Line Items]
Revenues	49,840		52,870		139,492		147,584
Operating profit (loss)	4,362		9,740		11,198		32,721
Net income (loss)	3,185		7,794		8,815		26,337
Operating segments | HBB
Segment Reporting Information [Line Items]
Revenues	135,155		134,099		354,865		354,901
Operating profit (loss)	9,531		11,788		12,719		18,461
Net income (loss)	6,008		7,427		7,717		10,913
Operating segments | KC
Segment Reporting Information [Line Items]
Revenues	37,551		42,618		107,231		120,709
Operating profit (loss)	(1,429)		(3,658)		(12,198)		(14,045)
Net income (loss)	(966)		(2,822)		(7,656)		(8,492)
Operating segments | NACCO and Other (a)
Segment Reporting Information [Line Items]
Operating profit (loss)	(1,073)	[1]	(1,155)	[1]	(4,429)	[1]	(4,690)	[1]
Net income (loss)	(906)		(1,137)		(3,776)		(4,188)
Selling, general and administrative expenses					1,100
Eliminations
Segment Reporting Information [Line Items]
Revenues	(832)		(973)		(2,091)		(2,511)
Operating profit (loss)	(68)		(33)		(443)		60
Net income (loss)	$ 378		$ 1,063		$ (2,549)		$ (2,676)

[1] During the second quarter of 2014, the Company recorded a $1.1 million charge included in selling, general and administrative expenses in NACCO and Other to correct a prior period accounting error related to an increase in the estimated liability for certain frozen deferred compensation plans. Management, quantitatively and qualitatively, assessed the materiality of the error and the correction thereof and concluded that the effect of the previous accounting treatment was not material to prior periods, expected 2014 full-year results, or trend of earnings and determined no material misstatements existed in those prior periods and no restatement of those prior period financial statements was necessary.