Acquisitions - Narrative (Details)							12 Months Ended
	Aug. 30, 2021 USD ($)	Aug. 09, 2021 USD ($) branch_location	Aug. 17, 2020 USD ($)	Mar. 11, 2020 USD ($) branch_location	Jul. 08, 2019 USD ($)	Feb. 04, 2019 USD ($)	Jan. 30, 2022 USD ($)	Jan. 31, 2021 USD ($)	Feb. 02, 2020 USD ($)
Business Acquisition [Line Items]
Goodwill acquired							$ 1,515,000,000	$ 1,453,000,000	$ 1,362,000,000
L&M
Business Acquisition [Line Items]
Transaction value	$ 60,000,000
Intangible assets purchase price allocation	19,000,000
Goodwill acquired	18,000,000
Upfront consideration payment for post-acquisition agreements	$ 0
Pacific Pipe
Business Acquisition [Line Items]
Transaction value		$ 103,000,000
Number of branch locations acquired | branch_location		4
Intangible assets purchase price allocation		$ 47,000,000
Goodwill acquired		41,000,000
Upfront consideration payment for post-acquisition agreements		$ 0
WWSC
Business Acquisition [Line Items]
Transaction value			$ 12,000,000
Net working capital purchase price allocation			3,000,000
Goodwill acquired			2,000,000
WWSC | Customer relationships
Business Acquisition [Line Items]
Intangible assets purchase price allocation			$ 6,000,000
R&B
Business Acquisition [Line Items]
Transaction value				$ 215,000,000
Number of branch locations acquired | branch_location				10
Intangible assets purchase price allocation				$ 114,000,000
Goodwill acquired				89,000,000
Initial cash consideration				212,000,000
Contingent consideration arrangement, low range of outcomes				0
Contingent consideration arrangement, high range of outcomes				$ 3,000,000
Post-acquisition service period				1 year
Fair value of contingent consideration recognized				$ 0
Upfront consideration payment for post-acquisition agreements				$ 0
LIP
Business Acquisition [Line Items]
Transaction value					$ 225,000,000
Number of branch locations acquired | branch_location				20
Intangible assets purchase price allocation					94,000,000
Goodwill acquired					51,000,000
Initial cash consideration				$ 220,000,000
Contingent consideration arrangement, high range of outcomes					5,000,000
Upfront consideration payment for post-acquisition agreements					$ (15,000,000)
Amortization of up-front consideration payment on post-acquisition agreements							2,000,000	$ 7,000,000	6,000,000
LIP | Minimum
Business Acquisition [Line Items]
Post-acquisition employment or consulting agreement term					1 year
LIP | Maximum
Business Acquisition [Line Items]
Post-acquisition employment or consulting agreement term					2 years
Maskell
Business Acquisition [Line Items]
Transaction value						$ 19,000,000
Fixed assets purchase price allocation						6,000,000
Net working capital purchase price allocation						2,000,000
Goodwill acquired						5,000,000
Maskell | Customer relationships
Business Acquisition [Line Items]
Intangible assets purchase price allocation						$ 5,000,000
Other acquisitions
Business Acquisition [Line Items]
Transaction value							$ 11,000,000		$ 2,000,000