Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2011	$ 322,112,000	$ 43,000	$ 0	$ 386,821,000	$ (1,830,000)	$ (65,085,000)	$ 2,163,000
Common stock, shares outstanding at Dec. 31, 2011		42,928,001
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to Acacia Research Corporation	59,453,000					59,453,000
Payments of Dividends	0
Sale of common stock, shares		6,122,449
Sale of common stock, value		6,000		218,955,000
Proceeds from Issuance or Sale of Equity	218,961,000
Treasury stock, shares acquired	1,129,408	(1,129,408)
Stock Repurchased During Period, Shares	(1,000)
Treasury stock, cost of shares acquired	(26,732,000)		(26,731,000)
Payments for Repurchase of Common Stock	26,732,000
Stock options exercised, shares		71,272
Stock options exercised, value	340,000			340,000
Stock issued during period, shares, share-based compensation, net of forfeitures		1,168,530
Compensation expense related to stock options and restricted stock awards	25,657,000	1,000		25,656,000
Excess tax benefits from stock-based compensation	13,210,000			13,210,000
Net (income) loss attributable to noncontrolling interests in operating subsidiaries	(164,000)						(164,000)
Contributions from noncontrolling interests in operating subsidiary, net	5,793,000						5,793,000
Distributions to noncontrolling interests in operating subsidiary	(816,000)						(816,000)
Unrealized gain on foreign currency translation	7,000
Unrealized gain (loss) on short-term investments	657,000
Balance at Dec. 31, 2012	618,478,000	49,000	(26,731,000)	644,982,000	(1,166,000)	(5,632,000)	6,976,000
Common stock, shares outstanding at Dec. 31, 2012		49,160,844
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to Acacia Research Corporation	(56,434,000)
Payments of Dividends	18,633,000
Sale of common stock, shares		0
Sale of common stock, value	(18,633,000)	0		(18,633,000)
Treasury stock, shares acquired		(600,000)
Stock Repurchased During Period, Shares	(1,000)	(666)
Treasury stock, cost of shares acquired	(7,910,000)		(7,909,000)
Payments for Repurchase of Common Stock	7,926,000			(16,000)
Stock options exercised, shares		115,346
Stock options exercised, value	486,000			486,000
Stock issued during period, shares, share-based compensation, net of forfeitures		709,533
Compensation expense related to stock options and restricted stock awards	27,894,000	1,000		27,893,000
Excess tax benefits from stock-based compensation	(1,398,000)
Net (income) loss attributable to noncontrolling interests in operating subsidiaries	(2,408,000)						(2,408,000)
Contributions from noncontrolling interests in operating subsidiary, net	1,920,000						1,920,000
Unrealized Gain (Loss) on Investments	219,000				219,000
Unrealized gain on foreign currency translation	0
Unrealized gain (loss) on short-term investments	26,000
Balance at Dec. 31, 2013	562,198,000	49,000	(34,640,000)	653,314,000	(947,000)	(62,066,000)	6,488,000
Common stock, shares outstanding at Dec. 31, 2013	49,385,057	49,385,057
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to Acacia Research Corporation	(66,029,000)
Payments of Dividends	25,039,000
Sale of common stock, value	(25,039,000)
Treasury stock, shares acquired	600,000
Payments for Repurchase of Common Stock	0
Stock options exercised, shares	45,000	44,506
Stock options exercised, value	206,000			206,000
Stock issued during period, shares, share-based compensation, net of forfeitures		635,819
Compensation expense related to stock options and restricted stock awards	18,115,000	1,000		18,114,000
Excess tax benefits from stock-based compensation	0
Net (income) loss attributable to noncontrolling interests in operating subsidiaries	(633,000)						(633,000)
Contributions from noncontrolling interests in operating subsidiary, net	(364,000)						(364,000)
Foreign Currency Transaction Gain (Loss), Unrealized					(99,000)
Unrealized Gain (Loss) on Investments	693,000				693,000
Unrealized gain on foreign currency translation	(128,000)
Unrealized gain (loss) on short-term investments	(1,488,000)
Balance at Dec. 31, 2014	$ 489,048,000	$ 50,000	$ (34,640,000)	$ 646,595,000	$ (353,000)	$ (128,095,000)	$ 5,491,000
Common stock, shares outstanding at Dec. 31, 2014	50,065,382	50,065,382