Acquisitions (Narrative) (Details) $ in Thousands			3 Months Ended			6 Months Ended
	Nov. 04, 2018 store	Oct. 14, 2018 store	Dec. 29, 2018 entity	Sep. 29, 2018 USD ($)	Sep. 23, 2017 USD ($)	Sep. 29, 2018 USD ($) store property	Sep. 23, 2017 USD ($) store
Business Acquisition [Line Items]
Costs related to completed acquisitions | $				$ 100	$ 200	$ 300	$ 300
Sales for acquired entities | $				$ 13,300	$ 3,100	18,700	$ 3,600
Change in estimates, inventories | $						(100)
Change in estimates, property, plant and equipment | $						(200)
Adjustments to goodwill related to purchase accounting | $						$ 300
Scenario, Forecast [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Number of acquisitions | entity			15
Jeff Pohlman Tire & Auto Service, Inc. [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Acquisition date	Nov. 04, 2018
Number of stores acquired	5
Quality Tire and Auto, Inc. [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Acquisition date		Oct. 14, 2018
Number of stores acquired		1
Walton’s Automotive, LLC. [Member]
Business Acquisition [Line Items]
Acquisition date						Sep. 23, 2018
Number of stores acquired						1
C&R Auto Service, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Sep. 16, 2018
Number of stores acquired						1
Steele-Guiltner, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Sep. 09, 2018
Number of stores acquired						4
Mayfair Tire & Service Center, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Jul. 15, 2018
Number of stores acquired						1
Sawyer Tire, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Jul. 08, 2018
Number of stores acquired						8
Free Service Tire Company, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						May 13, 2018
Number of stores acquired						12
Number of retread centers acquired | property						1
Number of wholesale centers acquired | property						4
Liberty Auto Group, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Apr. 01, 2018
Number of stores acquired						4
Auto MD, LLC. [Member]
Business Acquisition [Line Items]
Acquisition date						Aug. 13, 2017
Number of stores acquired							8
UVR, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Jul. 30, 2017
Number of stores acquired, both operating and not opened							13
Number of stores acquired							12
Number of stores never opened							1
Norman Young Tires, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Jul. 09, 2017
Number of stores acquired							1
D&S Pulaski, LLC. [Member]
Business Acquisition [Line Items]
Acquisition date						Jun. 25, 2017
Number of stores acquired							1
J & R Diversified, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Jun. 11, 2017
Number of stores acquired							2
Michael N. McGroarty, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Jun. 11, 2017
Number of stores acquired							1
Tires Plus LLC. [Member]
Business Acquisition [Line Items]
Acquisition date						Jun. 02, 2017
Number of stores acquired							1
Bob Sumerel Tire Co., Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						May 21, 2017
Number of stores acquired							1
Collier Automotive Group, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date						Apr. 23, 2017
Number of stores acquired							1
Fiscal 2018 Acquisitions [Member]
Business Acquisition [Line Items]
Total consideration transferred | $							$ 14,042
Fiscal 2019 Acquisitions [Member]
Business Acquisition [Line Items]
Total consideration transferred | $						$ 38,729