Stockholders' and Members' Equity, Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Mar. 30, 2022
Numerator [Abstract]
Net income attributable to OneWater Inc.	$ 8,900	$ 20,019
Effect of dilutive securities [Abstract]
Share repurchase program authorized amount			$ 50,000
Remaining amount available for future purchase	$ 49,600
Common Class A [Member]
Denominator [Abstract]
Weighted-average number of unrestricted outstanding common shares used to calculate basic net income per share (in shares)	14,297	13,380
Effect of dilutive securities [Abstract]
Restricted stock units (in shares)	284	381
Diluted weighted-average shares of Class A common stock outstanding used to calculate diluted earnings per share (in shares)	14,587	13,761
Earnings per share of Class A common stock - basic (in dollars per share)	$ 0.62	$ 1.5
Earnings per share of Class A common stock - diluted (in dollars per share)	$ 0.61	$ 1.45
Number of shares repurchased and retired (in shares)	10,134
Shares repurchased and retired	$ 400
Common Class A [Member] | Employee Stock Purchase Plan [Member]
Effect of dilutive securities [Abstract]
Restricted stock units (in shares)	6	0