Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Income before income taxes [Abstract]
United States		$ 55,980	$ 87,326	$ 57,846
Foreign		1,237	(231)	(5,873)
Income before income taxes		57,217	87,095	51,973
Current provision [Abstract]
Federal		16,178	30,623	19,758
State		2,866	4,098	2,553
Foreign		874	907	255
Total current provision		19,918	35,628	22,566
Deferred provision (benefit) [Abstract]
Federal		107	(2,653)	(1,183)
State		(455)	(1,213)	(275)
Foreign		57	345	(1,101)
Total deferred benefit		(291)	(3,521)	(2,559)
Total provision (benefit) [Abstract]
Federal		16,285	27,970	18,575
State		2,411	2,885	2,278
Foreign		931	1,252	(846)
Total income tax provision		19,627	32,107	20,007
Reconciliation of provision for income taxes [Abstract]
Tax at the statutory federal income tax rate		20,026	30,483	18,191
Qualified production activity deduction		(1,661)	(1,641)	(1,174)
State income tax, net of federal income tax		1,520	1,876	1,386
Other permanent differences		551	673	393
Research and development tax credits		(855)	(785)	(291)
Valuation allowance impact		1,585	1,638	2,036
U.S. Tax Reform impact		(1,056)	0	0
Other items		(483)	(137)	(534)
Total income tax provision		19,627	32,107	20,007
Deferred tax assets [Abstract]
Inventory reserves					$ 4,287	$ 8,507
Warranty reserves					3,560	4,527
Bad debt reserves					299	456
State tax loss carryforwards					2,710	3,403
Accrued vacation					1,712	2,351
SERP					367	299
Deferred compensation					1,293	2,124
Restricted stock units					1,664	1,845
Pension and post-employment benefits					1,448	2,530
Foreign net operating losses					6,310	5,461
Other					2,478	2,516
Valuation allowances	$ (8,318)	(8,318)	(8,280)	(6,029)	(8,318)	(8,280)
Total deferred tax assets					17,810	25,739
Deferred tax liabilities [Abstract]
Property and equipment					14,562	20,167
Intangibles					769	1,244
Goodwill					654	1,605
Pension					758	1,205
Outside basis differences					0	511
Total deferred tax liabilities					16,743	24,732
Total net deferred assets					1,067	1,007
Operating Loss Carryforwards [Line Items]
Recognized tax benefits related to penalties and interest settled for less than previously accrued		$ 22	16
Unrecognized tax benefits, if recognized that would effect the effective rate					370	$ 238
Period company does not expect significant increase or decrease to total amount of unrecognized tax benefits		12 months
Deferred Tax Asset Valuation Allowance [Roll Forward]
Allowance balance, beginning of year	8,318	$ 8,280	8,065	6,029
Provision		1,585	1,639	2,036
Write-offs		(1,862)	(289)	0
Other		315	(1,135)	0
Allowance balance, end of year		8,318	8,280	8,065
Reconciliation on unrecognized tax benefits [Roll forward]
Balance, beginning of year	$ 365	238	603	2,585
Additions for tax positions related to the current year		127	73	206
Additions for tax positions related to prior years		0	162	549
Reductions due to lapse of statutes of limitations		0	(16)	(162)
Decreases related to settlements with tax authorities		0	(584)	(2,575)
Balance, end of year		$ 365	$ 238	$ 603
Income Tax Disclosure [Line Items]
Federal corporate tax rate		35.00%
Provision of income tax expense (benefit)		$ (1,056)
Income tax expense (benefit)		(1,548)
Transition tax		492
Breaker Technology, Ltd. [Member]
Operating Loss Carryforwards [Line Items]
Undistributed earnings of foreign subsidiaries					4,026
Osborn Engineered Products [Member]
Operating Loss Carryforwards [Line Items]
Undistributed earnings of foreign subsidiaries					28,249
Plan [Member]
Income Tax Disclosure [Line Items]
Federal corporate tax rate	21.00%
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Increase in valuation allowance on operating loss carryforwards					7
Increase in other deferred tax assets valuation allowance		$ 31
Internal Revenue Service (IRS) [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, expiration date		Dec. 31, 2018
Internal Revenue Service (IRS) [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, expiration date		Dec. 31, 2030
State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards					17,579
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards					$ 19,876