Construction Partners, Inc. Annual report pursuant to Section 13 and 15(d)

Related Parties - Schedule of Related Party Transactions (Details) - Affiliated Entity - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Purchaser of subsidiary
Related Party Transaction [Line Items]
Revenue Earned (Expense Incurred)	$ 0	$ 0	$ 0
Receivable (Payable)	414	518
Disposed entity
Related Party Transaction [Line Items]
Revenue Earned (Expense Incurred)	0	0	0
Receivable (Payable)	264	330
Land Development Project
Related Party Transaction [Line Items]
Revenue Earned (Expense Incurred)	0	0	0
Receivable (Payable)	712	788
Subcontracting Services
Related Party Transaction [Line Items]
Revenue Earned (Expense Incurred)	(8,655)	(9,385)	(11,110)
Receivable (Payable)	(695)	(563)
Island Pond
Related Party Transaction [Line Items]
Revenue Earned (Expense Incurred)	(320)	(320)	(320)
Receivable (Payable)	0	0
SunTx
Related Party Transaction [Line Items]
Revenue Earned (Expense Incurred)	(1,451)	(1,935)	$ (1,403)
Receivable (Payable)	$ 0	$ 0