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Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands			3 Months Ended
	Feb. 11, 2020 $ / shares shares	Apr. 03, 2019 shares	Dec. 31, 2019 USD ($) Segment $ / shares shares	Dec. 31, 2018 shares	Sep. 30, 2019 USD ($) $ / shares	Mar. 28, 2014 shares
Public Offering [Abstract]
Common stock, par value (in dollars per share) \| $ / shares			$ 0.01		$ 0.01
Class A Common Stock [Member] \| Subsequent Event [Member]
Public Offering [Abstract]
Common stock, par value (in dollars per share) \| $ / shares	$ 0.01
Initial Public Offering [Member] \| Class A Common Stock [Member] \| Subsequent Event [Member]
Public Offering [Abstract]
Number of shares issued (in shares)	5,307,693
Common stock, par value (in dollars per share) \| $ / shares	$ 0.01
Number of shares issued on exercise of options (in shares)	692,308
Share price (in dollars per share) \| $ / shares	$ 12.00
OneWater LLC [Member]
Public Offering [Abstract]
Number of shares issued (in shares)		1,000
Deferred Offering Costs [Abstract]
Deferred offering costs \| $			$ 4,700		$ 2,600
Contract Liability [Abstract]
Beginning contract liability \| $			4,880
Revenue recognized from contract liabilities included in the beginning balance \| $			(4,673)
Increases due to cash received, net of amounts recognized in revenue during the period \| $			7,529
Ending contract liability \| $			$ 7,736
Segment Information [Abstract]
Number of operating segments \| Segment			1
Timing of Revenue [Abstract]
Percentage of revenue			100.00%
Earnings (Loss) per Share [Abstract]
Common units outstanding (in shares)			76,573	75,816		100,000
Weighted average common unit equivalents outstanding (in shares)			26,545	27,217
Diluted common unit equivalents (in shares)			103,118	103,033
OneWater LLC [Member] \| Class A Common Stock [Member]
Earnings (Loss) per Share [Abstract]
Common units outstanding (in shares)						73,140
OneWater LLC [Member] \| Transferred at Point in Time [Member]
Timing of Revenue [Abstract]
Percentage of revenue			94.90%
OneWater LLC [Member] \| Transferred over Time [Member]
Timing of Revenue [Abstract]
Percentage of revenue			5.10%