Industry Segment and Geographic Data, Customer Concentration (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) Customer		Dec. 31, 2019 USD ($)		Dec. 31, 2018 USD ($)
Customer Concentration [Abstract]
Revenues	$ 282,738	$ 343,609	$ 247,939	$ 254,302	$ 241,252	$ 307,723	$ 305,172	$ 283,766	$ 1,128,588	[1]	$ 1,137,913	[1]	$ 1,092,051	[1]
Large Retail Customer [Member] | Engine Management [Member]
Customer Concentration [Abstract]
Revenues									$ 140,000
Customer Concentration Risk [Member]
Customer Concentration [Abstract]
Number of largest individual customers | Customer									5
Net Sales [Member] | Customer Concentration Risk [Member] | Five Largest Individual Customers [Member]
Customer Concentration [Abstract]
Concentration risk, percentage									68.00%		69.00%		70.00%
Net Sales [Member] | Customer Concentration Risk [Member] | O' Reilly [Member]
Customer Concentration [Abstract]
Concentration risk, percentage									26.00%
Net Sales [Member] | Customer Concentration Risk [Member] | NAPA [Member]
Customer Concentration [Abstract]
Concentration risk, percentage									15.00%
Net Sales [Member] | Customer Concentration Risk [Member] | Advance [Member]
Customer Concentration [Abstract]
Concentration risk, percentage									14.00%
Net Sales [Member] | Customer Concentration Risk [Member] | AutoZone [Member]
Customer Concentration [Abstract]
Concentration risk, percentage									11.00%

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