Acquisitions (Narrative) (Details) $ in Thousands			12 Months Ended
	May 19, 2019 warehouse store	Mar. 31, 2019 store	Mar. 30, 2019 USD ($) property store	Mar. 31, 2018 USD ($) store
Business Acquisition [Line Items]
Store acquisitions related to acquisition growth strategy | property			5
Costs related to completed acquisitions | $			$ 600	$ 500
Sales for acquired entities | $			49,100	14,800
Net income (loss) for acquired entities | $			(500)	100
Change in estimates, inventories | $			(100)
Change in estimates, property, plant and equipment | $			(200)
Change in estimates, intangible assets | $			(200)
Adjustments to goodwill related to purchase accounting | $			$ 487	$ 1,331
Maximum [Member]
Business Acquisition [Line Items]
Store acquisitions related to greenfield store growth strategy | property			4
Minimum [Member]
Business Acquisition [Line Items]
Store acquisitions related to greenfield store growth strategy | property			1
Certified Tire And Service Centers, Inc. [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Acquisition date	May 19, 2019
Number of stores acquired	40
Number of distribution center | warehouse	1
Allied Discount Tire And Brake, Inc [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Acquisition date		Mar. 31, 2019
Number of stores acquired		12
Appalachian Tire Products, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date			Mar. 04, 2018
Number of stores acquired				7
Mattoon Muffler, Inc. and Charleston Muffler, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date			Mar. 04, 2018
Number of stores acquired				2
City Tire Co., Inc. [Member]
Business Acquisition [Line Items]
Acquisition date			Mar. 04, 2018
Number of stores acquired				1
Devenir Enterprises, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date			Mar. 01, 2018
Number of stores acquired				1
Valley Tire Co., Inc. [Member]
Business Acquisition [Line Items]
Acquisition date			Jan. 14, 2018
Number of stores acquired				3
R.A. Johnson, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date			Jan. 13, 2019
Number of stores acquired			13
Number of stores yet to open			1
Colony Tire Corporation [Member]
Business Acquisition [Line Items]
Acquisition date			Dec. 09, 2018
Number of stores acquired			2
Jeff Pohlman Tire & Auto Service, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date			Nov. 04, 2018
Number of stores acquired			5
Quality Tire and Auto, Inc. [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			1
Number of wholesale centers acquired			4
Liberty Auto Group, Inc. [Member]
Business Acquisition [Line Items]
Acquisition date			Apr. 01, 2018
Number of stores acquired			4
MLR, Incorporated [Member]
Business Acquisition [Line Items]
Acquisition date			Dec. 17, 2017
Number of stores acquired				1
TriGar Tire & Auto Service Center, LLC. [Member]
Business Acquisition [Line Items]
Acquisition date			Dec. 10, 2017
Number of stores acquired				2
TriGar Tire & Auto Service Center, LLC., Operated By Monro [Member]
Business Acquisition [Line Items]
Number of stores acquired				1
TriGar Tire & Auto Service Center, LLC., Operated By Mr. Tire [Member]
Business Acquisition [Line Items]
Number of stores acquired				1
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 | $				$ 22,624
Fiscal 2019 Acquisitions [Member]
Business Acquisition [Line Items]
Total consideration transferred | $			$ 61,617