Restatement of Previously Issued Financial Statements - Balance Sheets (Details) $ / shares in Units, shares in Thousands, $ in Thousands	Sep. 30, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Sep. 30, 2019 USD ($) $ / shares shares
Current assets
Cash and cash equivalents	$ 858	$ 2,142	$ 1,559
Trade receivables, net	98,062	108,381	103,091
Inventory	203,369	109,806	161,043
Prepaid expenses and other current assets	14,483	11,345	14,086
Current assets of discontinued operations	0	5,383	22,830
Total current assets	316,772	237,057	302,609
Property, plant and equipment, net	23,412	22,324	22,193
Goodwill	6,253	6,253	6,253
Other intangible assets, net	2,170	3,141	3,483
Deferred income taxes	6,078	6,248	5,640
Deferred costs	11,852	10,941	8,804
Other non-current assets	2,842	2,085	1,553
Non-current assets of discontinued operations	0	614	1,744
Total assets	369,379	288,663	352,279
Current liabilities
Accounts payable	187,296	111,348	140,011
Accounts payable to NACCO Industries, Inc.	496	496	220
Revolving credit agreements	70,413	23,497	50,152
Accrued compensation	14,294	15,027	14,650
Accrued product returns	6,575	8,697	8,266
Other current liabilities	17,338	12,534	25,880
Current liabilities of discontinued operations	0	29,723	24,713
Total current liabilities	296,412	201,322	263,892
Revolving credit agreements	0	35,000	30,000
Other long-term liabilities	12,567	16,075	14,258
Non-current liabilities of discontinued operations	0	0	1,585
Total liabilities	308,979	252,397	309,735
Stockholders' equity
Capital in excess of par value	58,225	54,509	54,143
Treasury stock	(5,960)	(5,960)	(5,960)
Retained earnings	27,219	3,710	12,231
Accumulated other comprehensive loss	(19,225)	(16,132)	(18,009)
Total stockholders' equity	60,400	36,266	42,544
Total liabilities and stockholders' equity	$ 369,379	$ 288,663	$ 352,279
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Class A Common stock
Stockholders' equity
Common stock	$ 100	$ 98	$ 95
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Common stock, shares issued (in shares) | shares	9,980	9,805	9,488
Class B Common stock
Stockholders' equity
Common stock	$ 41	$ 41	$ 44
Capital in excess of par value			54,143
Treasury stock			$ (5,960)
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Common stock, shares issued (in shares) | shares	4,055	4,076	4,377
Common stock, convertible conversion ratio	1	1	1
As Previously Reported
Current assets
Cash and cash equivalents		$ 2,142	$ 1,866
Trade receivables, net		113,781	106,135
Inventory		109,621	181,847
Prepaid expenses and other current assets		23,102	22,445
Current assets of discontinued operations		5,383	0
Total current assets		254,029	312,293
Property, plant and equipment, net		22,324	22,653
Goodwill		6,253	6,253
Other intangible assets, net		3,141	3,483
Deferred income taxes		3,853	6,161
Deferred costs		10,941	8,925
Other non-current assets		2,085	1,561
Non-current assets of discontinued operations		614	0
Total assets		303,240	361,329
Current liabilities
Accounts payable		111,117	147,206
Accounts payable to NACCO Industries, Inc.		496	220
Revolving credit agreements		23,497	59,702
Accrued compensation		14,277	15,568
Accrued product returns		8,697	8,266
Other current liabilities		12,873	30,651
Current liabilities of discontinued operations		29,723	0
Total current liabilities		200,680	261,613
Revolving credit agreements		35,000	30,000
Other long-term liabilities		12,501	14,961
Non-current liabilities of discontinued operations			0
Total liabilities		248,181	306,574
Stockholders' equity
Preferred stock, par value $0.01 per share		0
Capital in excess of par value		54,344
Treasury stock		(5,960)
Retained earnings		22,524	24,955
Accumulated other comprehensive loss		(15,988)	(18,522)
Total stockholders' equity		55,059	54,755
Total liabilities and stockholders' equity		303,240	361,329
As Previously Reported | Class A Common stock
Stockholders' equity
Common stock		98	95
As Previously Reported | Class B Common stock
Stockholders' equity
Common stock		41	44
Capital in excess of par value			54,143
Treasury stock			(5,960)
Restatement Impacts
Current assets
Cash and cash equivalents		0	0
Trade receivables, net		(5,400)	(2,179)
Inventory		185	0
Prepaid expenses and other current assets		(11,757)	(7,505)
Current assets of discontinued operations		0	0
Total current assets		(16,972)	(9,684)
Property, plant and equipment, net		0	0
Goodwill		0	0
Other intangible assets, net		0	0
Deferred income taxes		2,395	634
Deferred costs		0	0
Other non-current assets		0	0
Non-current assets of discontinued operations		0	0
Total assets		(14,577)	(9,050)
Current liabilities
Accounts payable		231	16
Accounts payable to NACCO Industries, Inc.		0	0
Revolving credit agreements		0	0
Accrued compensation		750	389
Accrued product returns		0	0
Other current liabilities		(339)	1,874
Current liabilities of discontinued operations		0	0
Total current liabilities		642	2,279
Revolving credit agreements		0	0
Other long-term liabilities		3,574	882
Non-current liabilities of discontinued operations			0
Total liabilities		4,216	3,161
Stockholders' equity
Preferred stock, par value $0.01 per share		0
Capital in excess of par value		165
Treasury stock		0
Retained earnings		(18,814)	(12,724)
Accumulated other comprehensive loss		(144)	513
Total stockholders' equity		(18,793)	(12,211)
Total liabilities and stockholders' equity		(14,577)	(9,050)
Restatement Impacts | Class A Common stock
Stockholders' equity
Common stock		0	0
Restatement Impacts | Class B Common stock
Stockholders' equity
Common stock		0	0
Capital in excess of par value			0
Treasury stock			0
As Restated
Current assets
Cash and cash equivalents		2,142	1,866
Trade receivables, net		108,381	103,956
Inventory		109,806	181,847
Prepaid expenses and other current assets		11,345	14,940
Current assets of discontinued operations		5,383	0
Total current assets		237,057	302,609
Property, plant and equipment, net		22,324	22,653
Goodwill		6,253	6,253
Other intangible assets, net		3,141	3,483
Deferred income taxes		6,248	6,795
Deferred costs		10,941	8,925
Other non-current assets		2,085	1,561
Non-current assets of discontinued operations		614	0
Total assets		288,663	352,279
Current liabilities
Accounts payable		111,348	147,222
Accounts payable to NACCO Industries, Inc.		496	220
Revolving credit agreements		23,497	59,702
Accrued compensation		15,027	15,957
Accrued product returns		8,697	8,266
Other current liabilities		12,534	32,525
Current liabilities of discontinued operations		29,723	0
Total current liabilities		201,322	263,892
Revolving credit agreements		35,000	30,000
Other long-term liabilities		16,075	15,843
Non-current liabilities of discontinued operations			0
Total liabilities		252,397	309,735
Stockholders' equity
Preferred stock, par value $0.01 per share		0
Capital in excess of par value		54,509
Treasury stock		(5,960)
Retained earnings		3,710	12,231
Accumulated other comprehensive loss		(16,132)	(18,009)
Total stockholders' equity		36,266	42,544
Total liabilities and stockholders' equity		288,663	352,279
As Restated | Class A Common stock
Stockholders' equity
Common stock		98	95
As Restated | Class B Common stock
Stockholders' equity
Common stock		$ 41	44
Capital in excess of par value			54,143
Treasury stock			(5,960)
Recasting Impacts
Current assets
Cash and cash equivalents			(307)
Trade receivables, net			(865)
Inventory			(20,804)
Prepaid expenses and other current assets			(854)
Current assets of discontinued operations			22,830
Total current assets			0
Property, plant and equipment, net			(460)
Goodwill			0
Other intangible assets, net			0
Deferred income taxes			(1,155)
Deferred costs			(121)
Other non-current assets			(8)
Non-current assets of discontinued operations			1,744
Total assets			0
Current liabilities
Accounts payable			(7,211)
Accounts payable to NACCO Industries, Inc.			0
Revolving credit agreements			(9,550)
Accrued compensation			(1,307)
Accrued product returns			0
Other current liabilities			(6,645)
Current liabilities of discontinued operations			24,713
Total current liabilities			0
Revolving credit agreements			0
Other long-term liabilities			(1,585)
Non-current liabilities of discontinued operations			1,585
Total liabilities			0
Stockholders' equity
Retained earnings			0
Accumulated other comprehensive loss			0
Total stockholders' equity			0
Total liabilities and stockholders' equity			0
Recasting Impacts | Class A Common stock
Stockholders' equity
Common stock			0
Recasting Impacts | Class B Common stock
Stockholders' equity
Common stock			0
Capital in excess of par value			0
Treasury stock			$ 0