Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Series A Redeemable Convertible Preferred Stock	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Comprehensive Income / Loss	Accumulated Deficit	Noncontrolling Interest	Total
Beginning balance, shares at Dec. 31, 2017	0	50,639,926
Beginning balance, value at Dec. 31, 2017	$ 0	$ 51	$ (34,640)	$ 648,996	$ (88)	$ (320,018)	$ 1,358	$ 295,659
Net loss attributable to Acacia Research Corporation						(105,029)		(105,029)
Cumulative effect of new accounting principle						2,506	308	2,814
Stock options exercised, shares		82,615
Stock options exercised, value				257				257
Compensation expense for share-based awards, net of forfeitures, shares		166,998
Compensation expense for share-based awards, net of forfeitures, value		$ 1		2,132				2,133
Repurchase of restricted common stock, shares		(59,800)
Repurchase of restricted common stock, value				(229)				(229)
Repurchase of common stock, shares		(1,190,420)
Repurchase of common stock, value		$ (2)	(4,632)					(4,634)
Net income (loss) attributable to noncontrolling interests in subsidiaries							181	181
Unrealized loss on foreign currency translation					88			88
Ending balance, shares at Dec. 31, 2018	0	49,639,319
Ending balance, value at Dec. 31, 2018	$ 0	$ 50	(39,272)	651,156	0	(422,541)	1,847	191,240
Net loss attributable to Acacia Research Corporation						(17,115)		(17,115)
Issuance of shares of Series A redeemable convertible preferred stock, net of embedded derivative, Series A warrants, and issuance costs, shares	350,000
Issuance of shares of Series A redeemable convertible preferred stock, net of embedded derivative, Series A warrants, and issuance costs, value	$ 7,782
Accretion of Series A redeemable convertible preferred stock to redemption value	$ 307			(307)				(307)
Stock options exercised, shares		25,136
Stock options exercised, value				79				79
Compensation expense for share-based awards, net of forfeitures, shares		706,532
Compensation expense for share-based awards, net of forfeitures, value				1,075				1,075
Net income (loss) attributable to noncontrolling interests in subsidiaries							(14)	(14)
Ending balance, shares at Dec. 31, 2019	350,000	50,370,987
Ending balance, value at Dec. 31, 2019	$ 8,089	$ 50	$ (39,272)	$ 652,003	$ 0	$ (439,656)	$ 1,833	$ 174,958