Revenues (Schedule Of Disaggregated Revenue By Product Group) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 23, 2017	Sep. 29, 2018	Sep. 23, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 307,105	$ 278,017	$ 602,916	$ 556,507
Brakes [Member]
Disaggregation of Revenue [Line Items]
Revenue	44,380	37,944	87,128	76,498
Exhaust [Member]
Disaggregation of Revenue [Line Items]
Revenue	8,264	7,201	15,623	14,413
Steering [Member]
Disaggregation of Revenue [Line Items]
Revenue	23,873	23,265	48,671	47,118
Tires [Member]
Disaggregation of Revenue [Line Items]
Revenue	150,522	134,553	291,252	267,063
Maintenance [Member]
Disaggregation of Revenue [Line Items]
Revenue	79,271	74,225	158,632	149,670
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 795	$ 829	$ 1,610	$ 1,745