Net Sales (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	$ 305,172	$ 286,636	$ 588,938	$ 548,462
Aftermarket [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	255,209	245,380	495,942	468,427
OE/OES [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	44,607	35,097	81,622	68,254
Export [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	5,356	6,159	11,374	11,781
Ignition, Emission Control, Fuel and Safety Related System Products [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	183,323	163,653	360,775	326,392
Wire and Cable [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	36,143	41,125	73,351	79,727
Compressors [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	53,285	47,758	92,836	77,600
Other Climate Control Parts [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	32,421	34,100	61,976	64,743
United States [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	274,782	257,836	527,527	490,954
Canada [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	12,771	13,917	24,952	27,129
Mexico [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	5,087	5,067	9,730	9,618
Europe [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	3,694	3,793	6,948	7,437
Other Foreign [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	8,838	6,023	19,781	13,324
Engine Management [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	218,042	203,429	431,231	402,917
Engine Management [Member] | Aftermarket [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	177,154	171,864	355,693	341,174
Engine Management [Member] | OE/OES [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	35,966	25,801	65,106	50,857
Engine Management [Member] | Export [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	4,922	5,764	10,432	10,886
Engine Management [Member] | Ignition, Emission Control, Fuel and Safety Related System Products [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	181,831	162,462	357,892	323,539
Engine Management [Member] | Wire and Cable [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	36,211	40,967	73,339	79,378
Engine Management [Member] | Compressors [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	0	0	0	0
Engine Management [Member] | Other Climate Control Parts [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	0	0	0	0
Engine Management [Member] | United States [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	194,127	181,845	382,021	358,762
Engine Management [Member] | Canada [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	6,736	7,288	13,802	15,092
Engine Management [Member] | Mexico [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	4,879	4,894	9,367	9,233
Engine Management [Member] | Europe [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	3,577	3,646	6,674	7,126
Engine Management [Member] | Other Foreign [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	8,723	5,756	19,367	12,704
Temperature Control [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	84,406	80,370	153,330	140,601
Temperature Control [Member] | Aftermarket [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	75,331	70,679	135,872	122,309
Temperature Control [Member] | OE/OES [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	8,641	9,296	16,516	17,397
Temperature Control [Member] | Export [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	434	395	942	895
Temperature Control [Member] | Ignition, Emission Control, Fuel and Safety Related System Products [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	0	0	0	0
Temperature Control [Member] | Wire and Cable [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	0	0	0	0
Temperature Control [Member] | Compressors [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	52,493	46,940	92,304	76,838
Temperature Control [Member] | Other Climate Control Parts [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	31,913	33,430	61,026	63,763
Temperature Control [Member] | United States [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	80,655	75,991	145,506	132,192
Temperature Control [Member] | Canada [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	3,311	3,792	6,773	7,093
Temperature Control [Member] | Mexico [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	208	173	363	385
Temperature Control [Member] | Europe [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	117	147	274	311
Temperature Control [Member] | Other Foreign [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1]	115	267	414	620
Other [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	2,724	2,837	4,377	4,944
Other [Member] | Aftermarket [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	2,724	2,837	4,377	4,944
Other [Member] | OE/OES [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	0	0	0	0
Other [Member] | Export [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	0	0	0	0
Other [Member] | Ignition, Emission Control, Fuel and Safety Related System Products [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	1,492	1,191	2,883	2,853
Other [Member] | Wire and Cable [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	(68)	158	12	349
Other [Member] | Compressors [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	792	818	532	762
Other [Member] | Other Climate Control Parts [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	508	670	950	980
Other [Member] | United States [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	0	0	0	0
Other [Member] | Canada [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	2,724	2,837	4,377	4,944
Other [Member] | Mexico [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	0	0	0	0
Other [Member] | Europe [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	0	0	0	0
Other [Member] | Other Foreign [Member]
Disaggregation of Revenue [Abstract]
Disaggregation of net sales	[1],[2]	$ 0	$ 0	$ 0	$ 0

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

[2] Other consists of the elimination of intersegment sales from our Engine Management and Temperature Control segments as well as sales from our Canadian business unit that does not meet the criteria of a reportable operating segment.  Intersegment wire and cable sales for the three months ended June 30, 2019 exceeded third party sales from our Canadian business unit.