Acquisitions - Finite-Lived and Indefinite-Lived Intangible Assets Acquired as Part of Business Combination (Details) $ in Millions	Jun. 30, 2022 USD ($)	Jun. 01, 2022 USD ($) branch	Apr. 29, 2022 USD ($) branch	Jan. 01, 2022 USD ($) branch	Dec. 31, 2021 USD ($)	Nov. 01, 2021 USD ($) branch	Jun. 30, 2021 USD ($)
Business Acquisition [Line Items]
Goodwill	$ 1,785.2				$ 1,777.4		$ 1,761.7
Complete Supply, Inc.
Business Acquisition [Line Items]
Number of branches acquired | branch		1
Goodwill		$ 9.1
Intangible Assets Acquired		$ 4.6
Wichita Falls Builders Wholesale, Inc.
Business Acquisition [Line Items]
Number of branches acquired | branch			1
Goodwill			$ 0.2
Intangible Assets Acquired			$ 0.5
Crabtree Siding and Supply
Business Acquisition [Line Items]
Number of branches acquired | branch				1
Goodwill				$ 0.1
Intangible Assets Acquired				$ 0.1
Midway Sales & Distributing, Inc.
Business Acquisition [Line Items]
Number of branches acquired | branch						10
Goodwill						$ 28.8
Intangible Assets Acquired						$ 38.5