Construction Partners, Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

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

Subsequent Events (Detail)

v3.20.4

Subsequent Events (Detail) $ in Millions			3 Months Ended	12 Months Ended
Subsequent Events (Detail) $ in Millions	Jan. 19, 2021 shares	Jan. 04, 2021 USD ($) shares	Dec. 31, 2019 shares	Sep. 30, 2019 USD ($) shares	Dec. 31, 2020 shares	Sep. 30, 2020 shares
Class B Common Stock
Subsequent Event [Line Items]
Conversion of Class B common stock to Class A common stock (in shares)			(107,682,000)
Common stock, shares issued (in shares)					20,828,813	20,828,813
Common stock, shares outstanding (in shares)					17,905,861	17,905,861
Class A Common Stock
Subsequent Event [Line Items]
Conversion of Class B common stock to Class A common stock (in shares)			107,682,000
Common stock, shares issued (in shares)					33,875,884	33,875,884
Common stock, shares outstanding (in shares)					33,875,884	33,875,884
Restricted Stock
Subsequent Event [Line Items]
Aggregate grant date fair value \| $				$ 3.8
Restricted Stock \| Class A Common Stock
Subsequent Event [Line Items]
Options granted (in shares)				292,534
Subsequent Event \| Class B Common Stock
Subsequent Event [Line Items]
Conversion of Class B common stock to Class A common stock (in shares)	148,621
Common stock, shares outstanding (in shares)	17,757,240
Subsequent Event \| Class A Common Stock
Subsequent Event [Line Items]
Conversion rate	1
Common stock, shares issued (in shares)	34,034,505
Subsequent Event \| Restricted Stock \| Vesting January 4, 2021
Subsequent Event [Line Items]
Vesting rate		25.00%
Subsequent Event \| Restricted Stock \| Vesting January 4, 2022
Subsequent Event [Line Items]
Vesting rate		25.00%
Subsequent Event \| Restricted Stock \| Vesting January 4, 2023
Subsequent Event [Line Items]
Vesting rate		25.00%
Subsequent Event \| Restricted Stock \| Vesting January 4, 2024
Subsequent Event [Line Items]
Vesting rate		25.00%
Subsequent Event \| Officer \| Restricted Stock
Subsequent Event [Line Items]
Options granted (in shares)		10,000
Aggregate grant date fair value \| $		$ 0.3

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