UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenues	$ 2,118	$ 5,460	$ 5,933	$ 8,847
Portfolio operations:
Inventor royalties	645	2,623	1,071	3,976
Contingent legal fees	12	375	246	552
Litigation and licensing expenses - patents	1,459	1,855	2,496	5,656
Amortization of patents	1,305	818	2,348	1,474
Other portfolio expenses (income)	(74)		(308)	650
Total portfolio operations	3,347	5,671	5,853	12,308
Net portfolio income (loss)	(1,229)	(211)	80	(3,461)
General and administrative expenses(1)	5,519	3,763	10,397	7,418
Operating loss	(6,748)	(3,974)	(10,317)	(10,879)
Other income (expense):
Change in fair value of investment, net (Note 5)	2,677	6,980	6,785	13,888
Gain (loss) on sale of investment (Note 5)	554	(1,642)	(2,762)	(7,232)
Impairment of other investment	0	(8,195)	0	(8,195)
Change in fair value of the Series A and B warrants and embedded derivatives	(62,902)	0	(67,284)	0
Change in fair value of equity securities derivative and forward contract	81,553	0	81,553	0
Change in fair value of trading securities	3,525	(61)	(2,592)	614
Gain (loss) on sale of trading securities	(7,121)	31	(7,009)	(12)
Loss on foreign currency exchange	(4,890)	0	(4,890)	0
Interest expense on Senior Secured Notes	(768)	0	(768)	0
Interest income and other	266	1,113	801	1,984
Total other income (expense)	12,894	(1,774)	3,834	1,047
Income (loss) before income taxes	6,146	(5,748)	(6,483)	(9,832)
Income tax benefit (expense)	2	(9)	1,340	(323)
Net income (loss) including noncontrolling interests in subsidiaries	6,148	(5,757)	(5,143)	(10,155)
Net loss attributable to noncontrolling interests in subsidiaries	0	0	0	14
Net income (loss) attributable to Acacia Research Corporation	6,148	(5,757)	(5,143)	(10,141)
Net income (loss) attributable to common stockholders - basic and diluted	$ 4,201	$ (5,757)	$ (7,105)	$ (10,141)
Basic net income (loss) per common share	$ 0.09	$ (0.12)	$ (0.14)	$ (0.20)
Weighted average number of shares outstanding - basic	48,457,620	49,696,016	49,166,508	49,676,059
Diluted net income (loss) per common share	$ 0.09	$ (0.12)	$ (0.14)	$ (0.20)
Weighted average number of shares outstanding - diluted	49,033,824	49,696,016	49,166,508	49,676,059