Business Combinations - Narrative (Details) $ in Thousands, $ in Millions					3 Months Ended								12 Months Ended
	Dec. 01, 2021 USD ($) location	Jul. 01, 2021 USD ($) location	Feb. 01, 2021 USD ($) location	Feb. 01, 2021 CAD ($)	Apr. 30, 2022 USD ($)	Jan. 31, 2022 USD ($)	Oct. 31, 2021 USD ($)	Jul. 31, 2021 USD ($)	Apr. 30, 2021 USD ($)	Jan. 31, 2021 USD ($)	Oct. 31, 2020 USD ($)	Jul. 31, 2020 USD ($)	Apr. 30, 2022 USD ($) location	Apr. 30, 2021 USD ($)	Apr. 30, 2020 USD ($)	Nov. 01, 2019
Business Acquisition [Line Items]
Net sales					$ 1,288,653	$ 1,153,595	$ 1,150,551	$ 1,042,076	$ 932,203	$ 751,191	$ 812,856	$ 802,573	$ 4,634,875	$ 3,298,823	$ 3,241,307
Net income					76,496	$ 61,383	$ 74,361	$ 61,202	33,746	$ 16,126	$ 28,469	$ 27,219	273,442	105,560	23,381
Transaction costs													$ 3,545	$ 1,068	2,414
Number of retail locations | location													100
Customer relationships
Business Acquisition [Line Items]
Estimated useful life (in years)													12 years 6 months	13 years 3 months 18 days
Tradenames
Business Acquisition [Line Items]
Estimated useful life (in years)													15 years 7 months 6 days	16 years 9 months 18 days
Fiscal Year 2022 Acquisitions
Business Acquisition [Line Items]
Net sales													$ 237,900
Net income													4,600
Westside Building Material
Business Acquisition [Line Items]
Preliminary consideration transferred		$ 140,108
Number of distribution network locations | location		10
Holdback liability		$ 13,500
Liability related to general representations and warranties, settlement period (in months)		15 months
Trade accounts and notes receivable		$ 27,081			26,282								26,282
Trade accounts and notes receivable, gross					26,400								26,400
Cash consideration		$ 126,608
Westside Building Material | Customer relationships
Business Acquisition [Line Items]
Estimated useful life (in years)		12 years
Westside Building Material | Tradenames
Business Acquisition [Line Items]
Estimated useful life (in years)		15 years
Westside Building Material | California
Business Acquisition [Line Items]
Number of distribution network locations | location		9
Westside Building Material | Nevada
Business Acquisition [Line Items]
Number of distribution network locations | location		1
Ames Taping Tools Holding LLC
Business Acquisition [Line Items]
Trade accounts and notes receivable	$ 9,955				9,901								9,901
Trade accounts and notes receivable, gross					$ 11,600								$ 11,600
Cash consideration	$ 226,700
Number of retail locations | location	100
Ames Taping Tools Holding LLC | Tradenames
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired	$ 23,000
Ames Taping Tools Holding LLC | Customer relationships
Business Acquisition [Line Items]
Estimated useful life (in years)	11 years
Ames Taping Tools Holding LLC | Tradenames
Business Acquisition [Line Items]
Estimated useful life (in years)	15 years
Finite-lived intangible assets acquired	$ 26,000
Ames Taping Tools Holding LLC | Patents
Business Acquisition [Line Items]
Estimated useful life (in years)	10 years
D.L. Building Materials Inc.
Business Acquisition [Line Items]
Preliminary consideration transferred			$ 38,900	$ 49.9
Trade accounts and notes receivable			$ 8,325						$ 8,301					$ 8,301
Outstanding common stock purchased (as a percent)			100.00%
Number of locations | location			2
2020 Acquisitions
Business Acquisition [Line Items]
Preliminary consideration transferred															$ 24,900
Rigney Building Supplies Ltd
Business Acquisition [Line Items]
Outstanding common stock purchased (as a percent)																100.00%