Construction Partners, Inc. Quarterly report [Sections 13 or 15(d)]

Quarterly report [Sections 13 or 15(d)]

Cover
- Cover Page
Financial Statements
Notes to Financial Statements
Accounting Policies
- Significant Accounting Policies (Policies)
Notes Tables
Notes Details

Significant Accounting Policies - Additional Information (Details)

v3.25.1

Significant Accounting Policies - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024	Sep. 30, 2024
Summary of Account Policies [Line Items]
Restricted cash	$ 1,729,000		$ 1,729,000		$ 1,998,000
Restricted investments	20,220,000		20,220,000		$ 18,020,000
Debt securities, available-for-sale, allowance for credit loss	$ 0	$ 0	$ 0	$ 0
Department of Transportation \| Revenues \| Customer Concentration Risk
Summary of Account Policies [Line Items]
Concentration risk percentage	40.90%	36.00%	37.20%	36.90%

- Definition

Summary Of Account Policies [Line Items]

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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.

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Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of cash restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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