Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Preferred stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss	Treasury stock	Parent	Noncontrolling interest	Series A Preferred Stock Preferred stock	Series A-1 Preferred Stock [Member]	Series A-1 Preferred Stock [Member] Preferred stock	Series B Preferred Stock	Series B Preferred Stock Preferred stock
Common stock, beginning balance (in shares) at Dec. 31, 2018		35,346					3,200
Preferred stock, beginning balance (in shares) at Dec. 31, 2018										127		0		355
Increase (Decrease) in Stockholders' Equity
Shares converted (in shares)										(2)		(125)		(2)
Partners' Capital Account, Exchange of Shares										125
Preferred Stock, Shares, Dividends Declared												3,577
Shares declared, not distributed												0
Common stock issued upon vesting of restricted stock		259
Common stock sold through offerings		2,960
Common stock repurchased through business combination							47
Tax withholding upon vesting of restricted stock							76
Preferred stock, ending balance (in shares) at Sep. 30, 2019										0		3,702		357
Common stock, ending balance (in shares) at Sep. 30, 2019		38,565					3,323
Beginning balance at Dec. 31, 2018				$ 657,981	$ (458,897)	$ (584)	$ (66,757)		$ 78,960
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Stock-based compensation to employees and directors				13,623
Adjustments to Additional Paid in Capital, Noncontrolling Interests									0
Proceeds from issuance and exercise of stock warrants	$ 52,112			52,112
Other				2,416	425				(3,266)
Net income (loss) attributable to stockholders of Overstock.com, Inc.	(94,863)				(94,863)
Net other comprehensive income	12					12
Common stock repurchased through business combination							(643)
Tax withholding upon vesting of restricted stock							(1,373)
Net loss attributable to noncontrolling interests	(10,197)								(10,197)
Ending balance at Sep. 30, 2019	168,952			726,132	(553,335)	(572)	$ (68,773)	$ 103,455	65,497
Common stock, beginning balance (in shares) at Dec. 31, 2018		35,346					3,200
Preferred stock, beginning balance (in shares) at Dec. 31, 2018										127		0		355
Increase (Decrease) in Stockholders' Equity
Preferred Stock, Shares, Dividends Declared											4,085
Preferred stock, ending balance (in shares) at Dec. 31, 2019										0	4,210	4,210	357	357
Common stock, ending balance (in shares) at Dec. 31, 2019		42,790					3,326
Beginning balance at Dec. 31, 2018				657,981	(458,897)	(584)	$ (66,757)		78,960
Ending balance at Dec. 31, 2019	177,855			764,845	(580,390)	(568)	$ (68,807)		62,771
Common stock, beginning balance (in shares) at Jun. 30, 2019		38,561					3,322
Preferred stock, beginning balance (in shares) at Jun. 30, 2019										3		123		356
Increase (Decrease) in Stockholders' Equity
Shares converted (in shares)										(1)		(2)		(1)
Partners' Capital Account, Exchange of Shares										2
Preferred Stock, Shares, Dividends Declared												3,577
Shares declared, not distributed												0
Common stock issued upon vesting of restricted stock		4
Common stock sold through offerings		0
Common stock repurchased through business combination							0
Tax withholding upon vesting of restricted stock							1
Preferred stock, ending balance (in shares) at Sep. 30, 2019										0		3,702		357
Common stock, ending balance (in shares) at Sep. 30, 2019		38,565					3,323
Beginning balance at Jun. 30, 2019				719,010	(522,397)	(576)	$ (68,746)		71,786
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Stock-based compensation to employees and directors				4,467
Adjustments to Additional Paid in Capital, Noncontrolling Interests									0
Proceeds from issuance and exercise of stock warrants				0
Other				2,655	0				(2,685)
Net income (loss) attributable to stockholders of Overstock.com, Inc.	(30,938)				(30,938)
Net other comprehensive income	4					4
Common stock repurchased through business combination							0
Tax withholding upon vesting of restricted stock							(27)
Net loss attributable to noncontrolling interests	(3,604)								(3,604)
Ending balance at Sep. 30, 2019	168,952			726,132	(553,335)	(572)	$ (68,773)	103,455	65,497
Preferred Stock, Value, Issued			$ 0
Increase (Decrease) in Stockholders' Equity
Common Stock, Value, Outstanding		$ 3
Total shares of common stock outstanding		35,242
Preferred Stock, Value, Issued											$ 0		$ 0
Common Stock, Value, Outstanding	$ 4
Total shares of common stock outstanding	39,464
Common stock, beginning balance (in shares) at Dec. 31, 2019		42,790					3,326
Preferred stock, beginning balance (in shares) at Dec. 31, 2019										0	4,210	4,210	357	357
Increase (Decrease) in Stockholders' Equity
Shares converted (in shares)										0		0		0
Partners' Capital Account, Exchange of Shares										0
Preferred Stock, Shares, Dividends Declared												0
Shares declared, not distributed												(6)
Common stock issued upon vesting of restricted stock		696
Common stock sold through offerings		2,831
Common stock repurchased through business combination							0
Tax withholding upon vesting of restricted stock							233
Preferred stock, ending balance (in shares) at Sep. 30, 2020										0	4,204	4,204	357	357
Common stock, ending balance (in shares) at Sep. 30, 2020		46,317					3,559
Beginning balance at Dec. 31, 2019	$ 177,855			764,845	(580,390)	(568)	$ (68,807)		62,771
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Stock-based compensation to employees and directors				8,356
Adjustments to Additional Paid in Capital, Noncontrolling Interests									5,000
Proceeds from issuance and exercise of stock warrants	195,540			192,692
Other				406	(113)				1,373
Net income (loss) attributable to stockholders of Overstock.com, Inc.	43,414				43,414
Net other comprehensive income	12					12
Common stock repurchased through business combination							0
Tax withholding upon vesting of restricted stock							(2,317)
Net loss attributable to noncontrolling interests	(7,372)								(7,372)
Ending balance at Sep. 30, 2020	419,306			966,299	(537,089)	(556)	$ (71,124)	357,534	61,772
Common stock, beginning balance (in shares) at Jun. 30, 2020		43,885					3,553
Preferred stock, beginning balance (in shares) at Jun. 30, 2020										0		4,204		357
Increase (Decrease) in Stockholders' Equity
Shares converted (in shares)										0		0		0
Partners' Capital Account, Exchange of Shares										0
Preferred Stock, Shares, Dividends Declared												0
Shares declared, not distributed												0
Common stock issued upon vesting of restricted stock		17
Common stock sold through offerings		2,415
Common stock repurchased through business combination							0
Tax withholding upon vesting of restricted stock							6
Preferred stock, ending balance (in shares) at Sep. 30, 2020										0	4,204	4,204	357	357
Common stock, ending balance (in shares) at Sep. 30, 2020		46,317					3,559
Beginning balance at Jun. 30, 2020				770,984	(560,480)	(560)	$ (70,537)		63,937
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Stock-based compensation to employees and directors				2,623
Adjustments to Additional Paid in Capital, Noncontrolling Interests									0
Proceeds from issuance and exercise of stock warrants				192,692
Other				0	0				0
Net income (loss) attributable to stockholders of Overstock.com, Inc.	23,391				23,391
Net other comprehensive income	4					4
Common stock repurchased through business combination							0
Tax withholding upon vesting of restricted stock							(587)
Net loss attributable to noncontrolling interests	(2,165)								(2,165)
Ending balance at Sep. 30, 2020	419,306			$ 966,299	$ (537,089)	$ (556)	$ (71,124)	$ 357,534	$ 61,772
Preferred Stock, Value, Issued			$ 0								$ 0		$ 0
Increase (Decrease) in Stockholders' Equity
Common Stock, Value, Outstanding	$ 4	$ 4
Total shares of common stock outstanding	42,758	42,758