Industry Segment and Geographic Data, Reportable Segments (Details) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) Segment		Dec. 31, 2018 USD ($)		Dec. 31, 2017 USD ($)
Financial information for reportable segment [Abstract]
Number of reportable operating segments | Segment										2
Net sales		$ 241,252	$ 307,723	$ 305,172	$ 283,766	$ 246,970	$ 296,619	$ 286,636	$ 261,826	$ 1,137,913	[1],[2]	$ 1,092,051	[1],[2]	$ 1,116,143	[1],[2],[3],[4]
Depreciation and amortization										25,809		24,104		23,916
Operating income (loss)										94,495		81,268		97,521
Investment in unconsolidated affiliates		38,858				32,469				38,858		32,469		31,184
Capital expenditures										16,185		20,141		24,442
Total assets		912,730				843,132				912,730		843,132		787,567
Intersegment Revenues [Member]
Financial information for reportable segment [Abstract]
Net sales	[2]									0		0		0	[3]
Engine Management [Member] | Reportable Segments [Member]
Financial information for reportable segment [Abstract]
Net sales	[2]									849,161		803,487		829,413	[3]
Depreciation and amortization										19,463		17,858		17,981
Operating income (loss)										103,808		84,844		97,403
Investment in unconsolidated affiliates		2,243				2,158				2,243		2,158		4,162
Capital expenditures										12,593		11,435		17,750
Total assets		601,637				553,480				601,637		553,480		527,200
Engine Management [Member] | Intersegment Revenues [Member]
Financial information for reportable segment [Abstract]
Net sales	[2]									19,569		23,367		24,995	[3]
Temperature Control [Member] | Reportable Segments [Member]
Financial information for reportable segment [Abstract]
Net sales	[2]									278,355		278,456		279,127	[3]
Depreciation and amortization										4,568		4,704		4,373
Operating income (loss)										13,667		14,586		19,609
Investment in unconsolidated affiliates		36,615				30,311				36,615		30,311		27,022
Capital expenditures										2,273		7,245		5,151
Total assets		218,783				205,039				218,783		205,039		177,006
Temperature Control [Member] | Intersegment Revenues [Member]
Financial information for reportable segment [Abstract]
Net sales	[2]									6,545		8,160		7,334	[3]
Other [Member]
Financial information for reportable segment [Abstract]
Net sales	[2]									10,397		10,108		7,603	[3]
Depreciation and amortization										1,778		1,542		1,562
Operating income (loss)										(22,980)		(18,162)		(19,491)
Investment in unconsolidated affiliates		0				0				0		0		0
Capital expenditures										1,319		1,461		1,541
Total assets		$ 92,310				$ 84,613				92,310		84,613		83,361
Other [Member] | Intersegment Revenues [Member]
Financial information for reportable segment [Abstract]
Net sales	[2]									$ (26,114)		$ (31,527)		$ (32,329)	[3]

[1] Revenues are attributed to countries based upon the location of the customer.

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

[3] Net sales and intersegment sales for 2017 have not been restated and are reported under accounting standards in effect in the period presented, as we adopted ASU 2014-09, Revenue from Contracts with Customers, on January 1, 2018 using the modified retrospective method.

[4] Revenues for 2017 have not been restated and are reported under accounting standards in effect in the period presented, as we adopted ASU 2014-09, Revenue from Contracts with Customers, on January 1, 2018 using the modified retrospective method.