EQUITY - Additional Information (Details)				9 Months Ended
	Jun. 12, 2020 USD ($) $ / shares shares	Apr. 30, 2020 Vote $ / shares	Mar. 24, 2020	Sep. 30, 2020 USD ($) Vote $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares
Equity [Line Items]
Total net proceeds from common stock and warrants sold | $				$ 68,602,000
Non-voting common share convert into voting common share				1
Percentage of voting power on contingent conversion triggering event				44.90%
Dividend declared date			Feb. 26, 2020	Feb. 26, 2020
Dividend payable date			May 29, 2020
Dividend record date			Apr. 10, 2020
Dividends payable | $				$ 2,400,000
Repurchase of warrants | $				879,000
Other-Long Term Liabilities and Other Current Liabilities [Member]
Equity [Line Items]
Dividends payable | $				$ 2,400,000	$ 2,400,000
Two Directors [Member] | Steiner [Member] | Minimum [Member]
Equity [Line Items]
Percentage of issued and outstanding common shares				15.00%
One Directors [Member] | Steiner [Member] | Minimum [Member]
Equity [Line Items]
Percentage of issued and outstanding common shares				5.00%
2020 Private Placement [Member]
Equity [Line Items]
Common stock and warrants sold | $	$ 75,000,000
Weighted average price | $ / shares				$ 10.50
2020 Private Placement [Member] | Steiner [Member]
Equity [Line Items]
Deferred shares issued				5,000,000
Public and Private Warrants [Member]
Equity [Line Items]
Warrants and rights Outstanding | $				$ 24,150,379
Repurchase of warrant shares				348,521
Repurchase of warrants | $				$ 900,000
Non-Voting Common Stock [Member]
Equity [Line Items]
Number of shares issued				17,186,000
Common stock, shares authorized				25,000,000	25,000,000
Common stock, par value | $ / shares				$ 0.0001	$ 0.0001
Common stock, shares issued				17,185,500	0
Common stock, shares outstanding				17,185,500	0
Non-Voting Common Stock [Member] | 2020 Private Placement [Member] | Steiner [Member]
Equity [Line Items]
Deferred shares issued				2,200,000
Voting Common Stock [Member]
Equity [Line Items]
Number of shares issued				6,564,000
Common stock, shares authorized				225,000,000	225,000,000
Common stock, par value | $ / shares				$ 0.0001	$ 0.0001
Common stock, shares issued				67,782,651	61,119,398
Common stock, shares outstanding				67,782,651	61,119,398
Voting Common Stock [Member] | 2020 Private Placement [Member] | Steiner [Member]
Equity [Line Items]
Deferred shares issued				2,800,000
Common Class A [Member]
Equity [Line Items]
Common stock, shares authorized				250,000,000
Common stock, par value | $ / shares				$ 0.0001
Number of common stock voting rights | Vote				1
Investment Agreement [Member] | Warrant [Member]
Equity [Line Items]
Warrant exercise price | $ / shares		$ 5.75
Number of common stock voting rights | Vote		1
Price per warrants | $ / shares		$ 0.01
Sales price of common shares | $ / shares		$ 14.50
Warrant expiration, description				will expire on the earlier of (i) the fifth anniversary of the closing of the 2020 Private Placement or (ii) the Redemption Date (as defined below). Each Warrant entitles the holder to purchase one share of OneSpaWorld common stock at an exercise price of $5.75. The 2020 Warrants may be exercised on a “cashless” basis, in accordance with a specified formula. In addition, the Company may, at any time prior to their expiration, elect to redeem not less than all of such then-outstanding 2020 Warrants at a price of $0.01 per warrant, provided that the last sales price of the common shares reported has been at least $14.50 per share (subject to adjustment in accordance with certain specified events), on each of twenty trading days within the thirty-trading day period ending on the third business day prior to the date on which notice of the redemption is given (the “Redemption Date”),
Warrants and rights Outstanding | $				$ 5,000,000
Investment Agreement [Member] | 2020 Private Placement [Member] | Steiner Leisure Limited [Member]
Equity [Line Items]
Common stock and warrants sold | $	75,000,000
Common stock and warrants sold offering expenses | $	6,400,000
Total net proceeds from common stock and warrants sold | $	$ 68,600,000
Investment Agreement [Member] | Non-Voting Common Stock [Member] | 2020 Private Placement [Member] | Steiner Leisure Limited [Member]
Equity [Line Items]
Number of shares issued	15,000,000
Warrants issued to purchase shares	4,000,000
Warrant exercise price | $ / shares	$ 5.75
Investment Agreement [Member] | Voting Common Stock [Member] | 2020 Private Placement [Member] | Co-Investors [Member]
Equity [Line Items]
Number of shares issued	3,700,000
Warrants issued to purchase shares	1,000,000
Warrant exercise price | $ / shares	$ 5.75
Business Combination Agreement [Member] | Steiner [Member]
Equity [Line Items]
Deferred shares issued				5,000,000