Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net loss including noncontrolling interests	$ (5,757)	$ (28,506)	$ (10,155)	$ (60,617)
Other comprehensive income (loss):
Unrealized gain (loss) on short-term investments, net of tax of $0	0	10	0	(10)
Unrealized gain (loss) on foreign currency translation, net of tax of $0	0	(87)	0	(104)
Total other comprehensive loss	(5,757)	(28,583)	(10,155)	(60,731)
Comprehensive loss attributable to noncontrolling interests	0	79	14	152
Comprehensive loss attributable to Acacia Research Corporation	$ (5,757)	$ (28,504)	$ (10,141)	$ (60,579)