Acquisitions (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Sep. 29, 2012
Kramer Acquisition
Business Acquisition [Line Items]
Annual sales based on unaudited pre-acquisition historical information	$ 25
Number of stores acquired	20
Number of heavy truck stores acquired	2
Number of wholesale operations acquired	2
Number of retread facilities acquired	1
Number of heavy truck stores disposed	2
Colony Acquisition
Business Acquisition [Line Items]
Annual sales based on unaudited pre-acquisition historical information	25
Number of stores acquired	18
Tuffy Acquisition
Business Acquisition [Line Items]
Annual sales based on unaudited pre-acquisition historical information	9
Number of stores acquired	17
Fiscal Year 2013 Closed Acquisitions [Member]
Business Acquisition [Line Items]
Total purchase price of completed acquisitions	57
Brothers Acquisition
Business Acquisition [Line Items]
Annual sales based on unaudited pre-acquisition historical information	1
Number of stores acquired	1
Chesley Acquisition
Business Acquisition [Line Items]
Annual sales based on unaudited pre-acquisition historical information	3
Number of stores acquired	5
Tire Barn Acquisition
Business Acquisition [Line Items]
Annual sales based on unaudited pre-acquisition historical information	$ 60
Number of stores acquired	31