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Summary of Significant Accounting Policies, Concentrations of Credit Risk (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) Customer	Dec. 31, 2017 USD ($)	Dec. 31, 2016
Concentration Risk [Abstract]
Foreign cash balance | $	$ 11.1	$ 13.1
Customer Concentration Risk [Member]
Concentration Risk [Abstract]
Number of largest individual customers | Customer	5
Net Sales [Member] | Customer Concentration Risk [Member]
Concentration Risk [Abstract]
Concentration risk, percentage	70.00%	70.00%	70.00%
Net Sales [Member] | Customer Concentration Risk [Member] | O' Reilly [Member]
Concentration Risk [Abstract]
Concentration risk, percentage	22.00%
Net Sales [Member] | Customer Concentration Risk [Member] | NAPA [Member]
Concentration Risk [Abstract]
Concentration risk, percentage	17.00%
Net Sales [Member] | Customer Concentration Risk [Member] | Advance [Member]
Concentration Risk [Abstract]
Concentration risk, percentage	16.00%
Net Sales [Member] | Customer Concentration Risk [Member] | AutoZone [Member]
Concentration Risk [Abstract]
Concentration risk, percentage	11.00%

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- Definition

Cash balances held in foreign currencies.

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- Definition

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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-Name Accounting Standards Codification
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