INCOME/LOSS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Net (loss) income attributable to Acacia Research Corporation	$ (61,503)	$ 19,660	$ (134,769)	$ (144,805)
Dividend on Series A redeemable convertible preferred stock	(699)	(263)	(1,399)	(523)
Accretion of Series A redeemable convertible preferred stock	(1,241)	(918)	(2,392)	(1,771)
Undistributed earnings allocated to participating securities	0	(3,245)	0	0
Net (loss) income attributable to common stockholders - Basic	(63,443)	15,234	(138,560)	(147,099)
Less: Change in fair value of Series A warrants	0	221	0	0
Less: Change in fair value of dilutive Series B warrants	0	1,355	0	0
Add: Interest expense associated with Starboard Notes, net of tax	0	1,238	0	0
Add: Undistributed earnings allocated to participating securities	0	3,245	0	0
Reallocation of undistributed earnings to participating securities	0	(2,365)	0	0
Net (loss) income attributable to common stockholders - Diluted	$ (63,443)	$ 18,928	$ (138,560)	$ (147,099)
Denominator:
Weighted average number of shares outstanding - Basic	43,988,677	48,729,020	45,259,435	48,662,897
Potentially dilutive common shares:
Potentially dilutive common shares (in shares)	43,988,677	83,086,980	45,259,435	48,662,897
Weighted average number of shares outstanding, diluted	43,988,677	83,086,980	45,259,435	48,662,897
Basic net (loss) income per common share (in usd per share)	$ (1.44)	$ 0.31	$ (3.06)	$ (3.02)
Diluted net (loss) income per common share (in usd per share)	$ (1.44)	$ 0.23	$ (3.06)	$ (3.02)
Anti-dilutive potential common shares excluded from the computation of diluted net (loss) income per share:
Antidilutive securities excluded from computation of earnings per share (in shares)	108,711,223	68,493,151	108,711,223	106,208,687
Restricted stock units
Potentially dilutive common shares:
Potentially dilutive common shares (in shares)	0	869,763	0	0
Stock options
Potentially dilutive common shares:
Potentially dilutive common shares (in shares)	0	46,858	0	0
Series A warrants
Potentially dilutive common shares:
Potentially dilutive common shares (in shares)	0	1,934,490	0	0
Series B warrants
Potentially dilutive common shares:
Potentially dilutive common shares (in shares)	0	31,506,849	0	0
Equity-based incentive awards
Anti-dilutive potential common shares excluded from the computation of diluted net (loss) income per share:
Antidilutive securities excluded from computation of earnings per share (in shares)	3,711,223	0	3,711,223	1,208,687
Series A warrants
Anti-dilutive potential common shares excluded from the computation of diluted net (loss) income per share:
Antidilutive securities excluded from computation of earnings per share (in shares)	5,000,000	0	5,000,000	5,000,000
Series B warrants
Anti-dilutive potential common shares excluded from the computation of diluted net (loss) income per share:
Antidilutive securities excluded from computation of earnings per share (in shares)	100,000,000	68,493,151	100,000,000	100,000,000