Concentrations of Risk - Schedule of Gross Sales by Major Customers (Details) - Customer A - Sales Revenue, Net - Customer Concentration Risk - Siding & Trim and Deck, Rail & Accessories - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024
Concentration Risk [Line Items]
Net sales	$ 546.4	$ 586.6	$ 558.2
Concentration risk, percentage	11.30%	15.10%	14.20%

Concentrations of Risk - Schedule of Gross Sales by Major Customers (Details) - Customer A - Sales Revenue, Net - Customer Concentration Risk - Siding & Trim and Deck, Rail & Accessories - USD ($)
$ in Millions

12 Months Ended

Mar. 31, 2026

Mar. 31, 2025

Mar. 31, 2024

Concentration Risk [Line Items]

Net sales

$ 546.4

$ 586.6

$ 558.2

Concentration risk, percentage

11.30%

15.10%

14.20%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References + Details

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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