Business Combinations and Dispositions- Additional Information (Detail) $ / shares in Units, shares in Thousands, $ in Thousands							3 Months Ended		9 Months Ended
	Sep. 01, 2021 USD ($)	Aug. 17, 2021 USD ($)	Jul. 26, 2021 USD ($)	Jul. 01, 2021 USD ($)	May 03, 2021 USD ($)	Jan. 01, 2021 USD ($) $ / shares shares	Sep. 30, 2021 USD ($) Segment shares	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) Segment shares	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) $ / shares shares
Business Combinations And Dispositions [Line Items]
Net sales							$ 5,508,590	$ 2,295,450	$ 15,259,047	$ 6,028,114
Income before income taxes							$ 801,486	$ 111,715	$ 1,670,041	$ 223,174
Fair value of intangible assets acquired	$ 1,771,550
Common stock, shares issued | shares							196,288		196,288		116,829
Common stock, shares outstanding | shares							196,288		196,288		116,829
Goodwill	2,366,213						$ 3,141,594		$ 3,141,594		$ 785,305
Number of reportable segment | Segment									1
Eastern U.S. Gypsum Distribution Operations
Business Combinations And Dispositions [Line Items]
Cash proceeds			$ 76,200
Total gain on sale			$ 26,300
Number of reportable segment | Segment							1		1
Customer Relationships
Business Combinations And Dispositions [Line Items]
Fair value of intangible assets acquired							$ 176,700		$ 176,700
Transaction related costs, incurred							6,500		7,200
John’s Lumber and Hardware Co
Business Combinations And Dispositions [Line Items]
Purchase price of certain assets acquired					$ 24,800
Goodwill							8,400		8,400
John’s Lumber and Hardware Co | Customer Relationships
Business Combinations And Dispositions [Line Items]
Fair value of intangible assets acquired							2,600		2,600
Cornerstone Building Alliance SW, LLC
Business Combinations And Dispositions [Line Items]
Purchase price of certain assets, net of cash acquired				$ 408,900
Goodwill							184,000		184,000
Cornerstone Building Alliance SW, LLC | Customer Relationships
Business Combinations And Dispositions [Line Items]
Fair value of intangible assets acquired							108,200		108,200
CTF Holdings Limited Partnership
Business Combinations And Dispositions [Line Items]
Purchase price of certain assets, net of cash acquired	$ 182,500
Goodwill							98,100		98,100
CTF Holdings Limited Partnership | Customer Relationships
Business Combinations And Dispositions [Line Items]
Fair value of intangible assets acquired							52,800		52,800
WTS Paradigm, LLC
Business Combinations And Dispositions [Line Items]
Fair value of intangible assets acquired		$ 124,900
Purchase price of certain assets, net of cash acquired		449,400
Goodwill		324,100
WTS Paradigm, LLC | Developed Technology
Business Combinations And Dispositions [Line Items]
Fair value of intangible assets acquired		$ 97,200
BMC Stock Holdings, Inc.
Business Combinations And Dispositions [Line Items]
Fair value of intangible assets acquired						$ 1,470,000
Common stock, shares issued | shares						88,683
Common stock, shares outstanding | shares						67,568
Purchase price of certain assets acquired						$ 3,658,362
Goodwill						$ 1,751,604
Transaction related expenses assumed									57,700
BMC Stock Holdings, Inc. | BMC
Business Combinations And Dispositions [Line Items]
Common stock price per share | $ / shares						$ 40.81
BMC Stock Holdings, Inc. | Merger Agreement
Business Combinations And Dispositions [Line Items]
Net sales							1,800,000		5,000,000
Income before income taxes							196,900		418,400
Long-term debt, assumed							359,800		359,800
Transaction related costs, incurred							0		17,600
Common stock, shares issued | shares											88,700
Common stock, shares outstanding | shares											900
BMC Stock Holdings, Inc. | Merger Agreement | Customer Relationships
Business Combinations And Dispositions [Line Items]
Fair value of intangible assets acquired							$ 1,500,000		$ 1,500,000
BMC Stock Holdings, Inc. | Merger Agreement | BMC
Business Combinations And Dispositions [Line Items]
Merger agreement date									Aug. 26, 2020
Common stock price per share | $ / shares											$ 40.81