Industry Segment and Geographic Data (Details) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) Customer Segment		Dec. 31, 2016 USD ($)		Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable operating segments | Segment										2
Financial information for reportable segment [Abstract]
Net sales		$ 239,978	$ 281,058	$ 312,729	$ 282,378	$ 229,799	$ 300,795	$ 288,977	$ 238,911	$ 1,116,143	[1]	$ 1,058,482	[1]	$ 971,975	[1]
Depreciation and amortization										23,916		20,457		17,637
Operating income (loss)										98,174		98,067		75,860
Investment in equity affiliates		31,184				19,924				31,184		19,924		20,622
Capital expenditures										24,442		20,921		18,047
Total assets		787,567				768,697				787,567		768,697		681,064
Reconciliation of segment operating income to net earnings [Abstract]
Operating income										98,174		98,067		75,860
Other non-operating income (expense)										597		2,059		(220)
Interest expense										2,329		1,556		1,537
Earnings from continuing operations before taxes										96,442		98,570		74,103
Income tax expense										52,812		36,158		25,983
Earnings from continuing operations		(8,106)	17,108	18,261	16,367	8,839	21,055	19,862	12,656	43,630		62,412		48,120
Discontinued operations, net of tax		(541)	(3,983)	(497)	(633)	(487)	(425)	(618)	(452)	(5,654)		(1,982)		(2,102)
Net earnings		(8,647)	13,125	17,764	15,734	8,352	20,630	19,244	12,204	37,976		60,430		46,018
Revenues [Abstract]
Revenues		239,978	$ 281,058	$ 312,729	$ 282,378	229,799	$ 300,795	$ 288,977	$ 238,911	1,116,143	[1]	1,058,482	[1]	971,975	[1]
Long-lived assets [Abstract]
Long-lived assets		259,056				243,349				$ 259,056		$ 243,349		$ 190,586
Customer Concentration Risk [Member]
Long-lived assets [Abstract]
Number of largest individual customers | Customer										5
Net Sales [Member] | Customer Concentration Risk [Member]
Long-lived assets [Abstract]
Concentration risk, percentage										70.00%		70.00%		68.00%
Net Sales [Member] | Customer Concentration Risk [Member] | O' Reilly Automotive, Inc. [Member]
Long-lived assets [Abstract]
Concentration risk, percentage										21.00%
Net Sales [Member] | Customer Concentration Risk [Member] | Advance Auto Parts, Inc. [Member]
Long-lived assets [Abstract]
Concentration risk, percentage										17.00%
Net Sales [Member] | Customer Concentration Risk [Member] | NAPA Auto Parts [Member]
Long-lived assets [Abstract]
Concentration risk, percentage										16.00%
Net Sales [Member] | Customer Concentration Risk [Member] | AutoZone, Inc [Member]
Long-lived assets [Abstract]
Concentration risk, percentage										10.00%
United States [Member]
Financial information for reportable segment [Abstract]
Net sales										$ 996,433		$ 952,019		$ 881,206
Revenues [Abstract]
Revenues										996,433		952,019		881,206
Long-lived assets [Abstract]
Long-lived assets		202,875				204,592				202,875		204,592		155,438
Canada [Member]
Financial information for reportable segment [Abstract]
Net sales										56,575		53,324		48,072
Revenues [Abstract]
Revenues										56,575		53,324		48,072
Long-lived assets [Abstract]
Long-lived assets		2,017				1,344				2,017		1,344		1,190
Mexico [Member]
Financial information for reportable segment [Abstract]
Net sales										24,521		24,429		14,707
Revenues [Abstract]
Revenues										24,521		24,429		14,707
Long-lived assets [Abstract]
Long-lived assets		4,449				3,877				4,449		3,877		1,012
Europe [Member]
Financial information for reportable segment [Abstract]
Net sales										14,088		14,703		16,305
Revenues [Abstract]
Revenues										14,088		14,703		16,305
Long-lived assets [Abstract]
Long-lived assets		18,530				13,612				18,530		13,612		12,324
Other Foreign [Member]
Financial information for reportable segment [Abstract]
Net sales										24,526		14,007		11,685
Revenues [Abstract]
Revenues										24,526		14,007		11,685
Long-lived assets [Abstract]
Long-lived assets		31,185				19,924				31,185		19,924		20,622
Intersegment Eliminations [Member]
Financial information for reportable segment [Abstract]
Net sales										0		0		0
Revenues [Abstract]
Revenues										0		0		0
Engine Management [Member] | Reportable Segments [Member]
Financial information for reportable segment [Abstract]
Net sales	[1]									829,413		765,539		698,021
Depreciation and amortization										17,981		15,008		12,256
Operating income (loss)										97,403		101,529		88,007
Investment in equity affiliates		4,162				6,221				4,162		6,221		6,430
Capital expenditures										17,750		14,202		13,038
Total assets		527,200				506,625				527,200		506,625		413,102
Reconciliation of segment operating income to net earnings [Abstract]
Operating income										97,403		101,529		88,007
Revenues [Abstract]
Revenues	[1]									829,413		765,539		698,021
Engine Management [Member] | Intersegment Eliminations [Member]
Financial information for reportable segment [Abstract]
Net sales										24,995		22,268		20,178
Revenues [Abstract]
Revenues										24,995		22,268		20,178
Engine Management [Member] | Ignition, Emission and Fuel System Parts [Member] | Reportable Segments [Member]
Financial information for reportable segment [Abstract]
Net sales	[1]									657,287		616,523		598,161
Revenues [Abstract]
Revenues	[1]									657,287		616,523		598,161
Engine Management [Member] | Wire and Cable [Member] | Reportable Segments [Member]
Financial information for reportable segment [Abstract]
Net sales	[1]									172,126		149,016		99,860
Revenues [Abstract]
Revenues	[1]									172,126		149,016		99,860
Temperature Control [Member] | Reportable Segments [Member]
Financial information for reportable segment [Abstract]
Net sales	[1]									279,127		283,740		264,478
Depreciation and amortization										4,373		4,287		4,329
Operating income (loss)										19,609		17,563		6,382
Investment in equity affiliates		27,022				13,703				27,022		13,703		14,192
Capital expenditures										5,151		3,652		3,027
Total assets		177,006				171,136				177,006		171,136		177,201
Reconciliation of segment operating income to net earnings [Abstract]
Operating income										19,609		17,563		6,382
Revenues [Abstract]
Revenues	[1]									279,127		283,740		264,478
Temperature Control [Member] | Intersegment Eliminations [Member]
Financial information for reportable segment [Abstract]
Net sales										7,334		7,293		6,542
Revenues [Abstract]
Revenues										7,334		7,293		6,542
Temperature Control [Member] | Compressors [Member] | Reportable Segments [Member]
Financial information for reportable segment [Abstract]
Net sales	[1]									148,377		148,623		127,861
Revenues [Abstract]
Revenues	[1]									148,377		148,623		127,861
Temperature Control [Member] | Other Climate Control Parts [Member] | Reportable Segments [Member]
Financial information for reportable segment [Abstract]
Net sales	[1]									130,750		135,117		136,617
Revenues [Abstract]
Revenues	[1]									130,750		135,117		136,617
Other [Member]
Financial information for reportable segment [Abstract]
Net sales	[1]									7,603		9,203		9,476
Depreciation and amortization										1,562		1,162		1,052
Operating income (loss)										(18,838)		(21,025)		(18,529)
Investment in equity affiliates		0				0				0		0		0
Capital expenditures										1,541		3,067		1,982
Total assets		$ 83,361				$ 90,936				83,361		90,936		90,761
Reconciliation of segment operating income to net earnings [Abstract]
Operating income										(18,838)		(21,025)		(18,529)
Revenues [Abstract]
Revenues	[1]									7,603		9,203		9,476
Other [Member] | Intersegment Eliminations [Member]
Financial information for reportable segment [Abstract]
Net sales										(32,329)		(29,561)		(26,720)
Revenues [Abstract]
Revenues										$ (32,329)		$ (29,561)		$ (26,720)

[1] Segment and product line net sales include intersegment sales in our Engine Management and Temperature Control segments.