Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Revenues from external customers	$ 196,052	$ 173,679
Operating profit (loss)	7,022	8,068
Income from continuing operations	4,422	4,712
NACoal
Segment Reporting Information [Line Items]
Revenues from external customers	51,147	24,334
Operating profit (loss)	11,785	11,928
Income from continuing operations	9,591	9,207
HBB
Segment Reporting Information [Line Items]
Revenues from external customers	106,151	104,940
Operating profit (loss)	2,668	2,151
Income from continuing operations	1,501	1,027
KC
Segment Reporting Information [Line Items]
Revenues from external customers	39,711	45,293
Operating profit (loss)	(4,980)	(4,578)
Income from continuing operations	(3,267)	(2,817)
NACCO and Other
Segment Reporting Information [Line Items]
Operating profit (loss)	(2,436)	(1,514)
Income from continuing operations	(2,003)	(1,452)
Eliminations
Segment Reporting Information [Line Items]
Revenues from external customers	(957)	(888)
Operating profit (loss)	(15)	81
Income from continuing operations	$ (1,400)	$ (1,253)