CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	2020 Private Placement [Member]	At-the- Market Equity Offering [Member]	Voting Common Stock [Member]	Voting Common Stock [Member] 2020 Private Placement [Member]	Voting Common Stock [Member] At-the- Market Equity Offering [Member]	Non-Voting Common Stock [Member]	Non-Voting Common Stock [Member] 2020 Private Placement [Member]	Voting and Non-Voting Common Stock [Member]	Voting and Non-Voting Common Stock [Member] 2020 Private Placement [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] 2020 Private Placement [Member]	Additional Paid-in Capital [Member] At-the- Market Equity Offering [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	Total OneSpaWorld Stockholders' Equity [Member]	Total OneSpaWorld Stockholders' Equity [Member] 2020 Private Placement [Member]	Non-Controlling Interest [Member]
BALANCE at Dec. 31, 2019	$ 590,468								$ 6		$ 616,888			$ 719	$ (35,269)	$ 582,344		$ 8,124
BALANCE (In Shares) at Dec. 31, 2019				61,119
Net loss	(216,602)														(216,602)	(216,602)
Net of issuance costs		$ 53,788								$ 3		$ 53,785					$ 53,788
Net of issuance costs, Shares					6,564			17,186
Reclassification of public warrants to liabilities	(26,500)										(26,500)					(26,500)
Stock-based compensation	1,960										1,960					1,960
Foreign currency translation adjustment	(215)													(215)		(215)
Unrecognized gain (loss) on derivatives	(6,291)													(6,291)		(6,291)
Dividend declared	(2,449)										(2,449)					(2,449)
Distributions to noncontrolling interest	(4,011)																	(4,011)
Purchase of noncontrolling interest	(10,810)										(6,697)					(6,697)		$ (4,113)
Purchase of noncontrolling interest, Shares				99
Purchase of public warrants	(879)										(879)					(879)
BALANCE at Sep. 30, 2020	378,459								9		636,108			(5,787)	(251,871)	378,459
BALANCE (In Shares) at Sep. 30, 2020				67,782			17,186
BALANCE at Jun. 30, 2020	424,414								9		634,998			(6,269)	(204,324)
BALANCE (In Shares) at Jun. 30, 2020				67,782			17,186
Net loss	(47,547)														(47,547)
Stock-based compensation	1,110										1,110
Foreign currency translation adjustment	89													89
Unrecognized gain (loss) on derivatives	393													393
BALANCE at Sep. 30, 2020	378,459								9		636,108			(5,787)	(251,871)	$ 378,459
BALANCE (In Shares) at Sep. 30, 2020				67,782			17,186
BALANCE at Dec. 31, 2020	320,828								9		649,540			(5,475)	(323,246)
BALANCE (In Shares) at Dec. 31, 2020				69,292			17,186
Net loss	(57,605)														(57,605)
Net of issuance costs			$ 23,968										$ 23,968
Net of issuance costs, Shares						2,264
Stock-based compensation	7,419										7,419
Foreign currency translation adjustment	(90)													(90)
Unrecognized gain (loss) on derivatives	2,085													2,085
Common shares issued under equity incentive plan, Shares				1,015
Conversion of deferred shares into common shares, Shares				1,600
Conversion of public warrants into common shares (In Shares)				5
BALANCE at Sep. 30, 2021	296,605								9		680,927			(3,480)	(380,851)
BALANCE (In Shares) at Sep. 30, 2021				74,176			17,186
BALANCE at Jun. 30, 2021	301,199								9		673,375			(3,676)	(368,509)
BALANCE (In Shares) at Jun. 30, 2021				73,290			17,186
Net loss	(12,342)														(12,342)
Net of issuance costs			$ 5,493										$ 5,493
Net of issuance costs, Shares						552
Stock-based compensation	2,059										2,059
Foreign currency translation adjustment	(204)													(204)
Unrecognized gain (loss) on derivatives	400													400
Common shares issued under equity incentive plan, Shares				334
BALANCE at Sep. 30, 2021	$ 296,605								$ 9		$ 680,927			$ (3,480)	$ (380,851)
BALANCE (In Shares) at Sep. 30, 2021				74,176			17,186