CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Revenues
Total revenues		$ 1,022,970
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales		787,446
Selling, general and administrative expenses		143,396
Depreciation and amortization		3,249	$ 2,682	$ 1,685
Transaction costs		3,648	1,323
Loss (gain) on contingent consideration		6,762
Income from operations		78,469
Other expense (income)
Interest expense - floor plan		8,861
Interest expense - other		8,828
Change in fair value of warrant liability		(771)	(1,336)	33,187
Loss (gain) on extinguishment of debt		6,559	0	(209)
Other expense (income), net		155
Total other expense (income), net		23,632
Income before income tax expense		54,837
Income tax expense		6,329
Net income		48,508	37,263	1,946
Less: Net income attributable to non-controlling interest		(350)
Net income attributable to One Water Marine Holdings, LLC		$ 17,425
Earnings per share, Basic (in dollars per share)		$ 2.79
Earnings per share, Diluted (in dollars per share)		$ 2.77
Weighted average number of shares outstanding, Basic (in shares)		6,243
Weighted average number of shares outstanding, Diluted (in shares)		6,287
Class A Common Stock [Member]
Other expense (income)
Earnings per share, Basic (in dollars per share)	[1]	$ 2.79
Earnings per share, Diluted (in dollars per share)	[1]	$ 2.77
Weighted average number of shares outstanding, Basic (in shares)	[1]	6,243
Weighted average number of shares outstanding, Diluted (in shares)	[1]	6,287
New Boat [Member]
Revenues
Total revenues		$ 717,093
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales		585,720
Pre-Owned Boat [Member]
Revenues
Total revenues		205,650
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales		168,261
Finance & Insurance [Member]
Revenues
Total revenues		36,792
Service, Parts & Other [Member]
Revenues
Total revenues		63,435
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales		33,465
OneWater LLC [Member]
Revenues
Total revenues			767,624	602,805
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales			595,498	465,151
Selling, general and administrative expenses			116,503	91,297
Depreciation and amortization			2,682	1,685
Transaction costs			1,323	438
Loss (gain) on contingent consideration			(1,674)	0
Income from operations			53,292	44,234
Other expense (income)
Interest expense - floor plan			9,395	5,534
Interest expense - other			6,568	3,836
Change in fair value of warrant liability			(1,336)	33,187
Loss (gain) on extinguishment of debt			0	(209)
Other expense (income), net			1,402	(60)
Total other expense (income), net			16,029	42,288
Income before income tax expense			37,263	1,946
Income tax expense			0	0
Net income			37,263	1,946
Less: Net income attributable to non-controlling interest		$ (30,733)	(1,606)	(830)
Net income attributable to One Water Marine Holdings, LLC			35,657	1,116
OneWater LLC [Member] | New Boat [Member]
Revenues
Total revenues			526,774	409,947
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales			434,242	332,728
OneWater LLC [Member] | Pre-Owned Boat [Member]
Revenues
Total revenues			153,010	129,570
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales			127,018	105,855
OneWater LLC [Member] | Finance & Insurance [Member]
Revenues
Total revenues			26,151	16,623
OneWater LLC [Member] | Service, Parts & Other [Member]
Revenues
Total revenues			61,689	46,665
Cost of sales (exclusive of depreciation and amortization shown separately below)
Total cost of sales			$ 34,238	$ 26,568

[1] Represents earnings per share of Class A common stock and weighted-average shares of Class A common stock outstanding for the period from February 11, 2020 through September 30, 2020, the period following the Organizational Transactions (as defined below) and OneWater Marine Inc.'s initial public offering. See Note 1.