Restatement of Previously Issued Financial Statements - Balance Sheets (Details) $ / shares in Units, shares in Thousands, $ in Thousands	Mar. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Mar. 31, 2019 USD ($) $ / shares shares
Current assets
Cash and cash equivalents	$ 2,078	$ 2,142	$ 1,636
Trade receivables, net	69,569	108,381	79,102
Inventory	89,986	109,806	120,707
Prepaid expenses and other current assets	16,427	11,345	17,379
Current assets of discontinued operations	324	5,383	24,692
Total current assets	178,384	237,057	243,516
Property, plant and equipment, net	22,465	22,324	20,984
Goodwill	6,253	6,253	6,253
Other intangible assets, net	2,818	3,141	4,174
Deferred income taxes	5,128	6,248	3,166
Deferred costs	11,172	10,941	8,316
Other non-current assets	2,150	2,085	2,403
Non-current assets of discontinued operations	0	614	4,446
Total assets	228,370	288,663	293,258
Current liabilities
Accounts payable	61,578	111,348	73,720
Accounts payable to NACCO Industries, Inc.	496	496	2,425
Revolving credit agreements	34,547	23,497	54,812
Accrued compensation	8,126	15,027	8,398
Accrued product returns	7,536	8,697	9,314
Other current liabilities	14,097	12,534	17,705
Current liabilities of discontinued operations	1,099	29,723	21,473
Total current liabilities	127,478	201,322	187,847
Revolving credit agreements	35,000	35,000	30,000
Other long-term liabilities	12,493	16,075	18,619
Non-current liabilities of discontinued operations	0	0	3,834
Total liabilities	174,972	252,397	240,300
Stockholders' equity
Preferred stock, par value $0.01 per share		0
Capital in excess of par value	55,062	54,509	52,520
Treasury stock	(5,960)	(5,960)	0
Retained earnings	23,996	3,710	17,506
Accumulated other comprehensive loss	(19,842)	(16,132)	(17,207)
Total stockholders' equity	53,396	36,266	52,958
Total liabilities and stockholders' equity	$ 228,370	$ 288,663	$ 293,258
Preferred stock, par value (in usd per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Class A Common Stock
Stockholders' equity
Common stock	$ 99	$ 98	$ 95
Common stock, par value (in usd per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Common stock, shares, issued (in shares) | shares	9,917	9,805	9,457
Class B Common Stock
Stockholders' equity
Common stock	$ 41	$ 41	$ 44
Capital in excess of par value			$ 52,520
Common stock, par value (in usd per share) | $ / shares	$ 0.01	$ 0.01	$ 0.01
Common stock, shares, issued (in shares) | shares	4,074	4,076	4,385
Common stock, convertible conversion ratio	1	1	1
As Previously Reported
Current assets
Cash and cash equivalents		$ 2,142	$ 1,721
Trade receivables, net		113,781	92,534
Inventory		109,621	142,261
Prepaid expenses and other current assets		23,102	16,373
Current assets of discontinued operations		5,383	0
Total current assets		254,029	252,889
Property, plant and equipment, net		22,324	22,566
Goodwill		6,253	6,253
Other intangible assets, net		3,141	4,174
Deferred income taxes		3,853	5,493
Deferred costs		10,941	8,447
Other non-current assets		2,085	2,424
Non-current assets of discontinued operations		614	0
Total assets		303,240	302,246
Current liabilities
Accounts payable		111,117	80,649
Accounts payable to NACCO Industries, Inc.		496	2,425
Revolving credit agreements		23,497	62,212
Accrued compensation		14,277	8,903
Accrued product returns		8,697	9,314
Other current liabilities		12,873	24,109
Current liabilities of discontinued operations		29,723	0
Total current liabilities		200,680	187,612
Revolving credit agreements		35,000	32,000
Other long-term liabilities		12,501	19,555
Non-current liabilities of discontinued operations		0	0
Total liabilities		248,181	239,167
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	27,959
Accumulated other comprehensive loss		(15,988)	(17,539)
Total stockholders' equity		55,059	63,079
Total liabilities and stockholders' equity		$ 303,240	302,246
Preferred stock, par value (in usd per share) | $ / shares		$ 0.01
As Previously Reported | Class A Common Stock
Stockholders' equity
Common stock		$ 98	95
Common stock, par value (in usd per share) | $ / shares		$ 0.01
Common stock, shares, issued (in shares) | shares		9,805
As Previously Reported | Class B Common Stock
Stockholders' equity
Common stock		$ 41	44
Capital in excess of par value			52,520
Common stock, par value (in usd per share) | $ / shares		$ 0.01
Common stock, shares, issued (in shares) | shares		4,076
Common stock, convertible conversion ratio		1
Restatement Impacts
Current assets
Cash and cash equivalents		$ 0	0
Trade receivables, net		(5,400)	(2,768)
Inventory		185	0
Prepaid expenses and other current assets		(11,757)	(6,605)
Current assets of discontinued operations		0	0
Total current assets		(16,972)	(9,373)
Property, plant and equipment, net		0	0
Goodwill		0	0
Other intangible assets, net		0	0
Deferred income taxes		2,395	385
Deferred costs		0	0
Other non-current assets		0	0
Non-current assets of discontinued operations		0	0
Total assets		(14,577)	(8,988)
Current liabilities
Accounts payable		231	0
Accounts payable to NACCO Industries, Inc.		0	0
Revolving credit agreements		0	0
Accrued compensation		750	370
Accrued product returns		0	0
Other current liabilities		(339)	(135)
Current liabilities of discontinued operations		0	0
Total current liabilities		642	235
Revolving credit agreements		0	0
Other long-term liabilities		3,574	898
Non-current liabilities of discontinued operations		0	0
Total liabilities		4,216	1,133
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)	(10,453)
Accumulated other comprehensive loss		(144)	332
Total stockholders' equity		(18,793)	(10,121)
Total liabilities and stockholders' equity		$ (14,577)	(8,988)
Preferred stock, par value (in usd per share) | $ / shares		$ 0.01
Restatement Impacts | Class A Common Stock
Stockholders' equity
Common stock		$ 0	0
Common stock, par value (in usd per share) | $ / shares		$ 0.01
Common stock, shares, issued (in shares) | shares		9,805
Restatement Impacts | Class B Common Stock
Stockholders' equity
Common stock		$ 0	0
Capital in excess of par value			0
Common stock, par value (in usd per share) | $ / shares		$ 0.01
Common stock, shares, issued (in shares) | shares		4,076
Common stock, convertible conversion ratio		1
As Restated
Current assets
Cash and cash equivalents			1,721
Trade receivables, net			89,766
Inventory			142,261
Prepaid expenses and other current assets			9,768
Current assets of discontinued operations			0
Total current assets			243,516
Property, plant and equipment, net			22,566
Goodwill			6,253
Other intangible assets, net			4,174
Deferred income taxes			5,878
Deferred costs			8,447
Other non-current assets			2,424
Non-current assets of discontinued operations			0
Total assets			293,258
Current liabilities
Accounts payable			80,649
Accounts payable to NACCO Industries, Inc.			2,425
Revolving credit agreements			62,212
Accrued compensation			9,273
Accrued product returns			9,314
Other current liabilities			23,974
Current liabilities of discontinued operations			0
Total current liabilities			187,847
Revolving credit agreements			32,000
Other long-term liabilities			20,453
Non-current liabilities of discontinued operations			0
Total liabilities			240,300
Stockholders' equity
Retained earnings			17,506
Accumulated other comprehensive loss			(17,207)
Total stockholders' equity			52,958
Total liabilities and stockholders' equity			293,258
As Restated | Class A Common Stock
Stockholders' equity
Common stock			95
As Restated | Class B Common Stock
Stockholders' equity
Common stock			44
Capital in excess of par value			52,520
Recasting Impacts
Current assets
Cash and cash equivalents			(85)
Trade receivables, net			(10,664)
Inventory			(21,554)
Prepaid expenses and other current assets			7,611
Current assets of discontinued operations			24,692
Total current assets			0
Property, plant and equipment, net			(1,582)
Goodwill			0
Other intangible assets, net			0
Deferred income taxes			(2,712)
Deferred costs			(131)
Other non-current assets			(21)
Non-current assets of discontinued operations			4,446
Total assets			0
Current liabilities
Accounts payable			(6,929)
Accounts payable to NACCO Industries, Inc.			0
Revolving credit agreements			(7,400)
Accrued compensation			(875)
Accrued product returns			0
Other current liabilities			(6,269)
Current liabilities of discontinued operations			21,473
Total current liabilities			0
Revolving credit agreements			(2,000)
Other long-term liabilities			(1,834)
Non-current liabilities of discontinued operations			3,834
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