Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
Revenues	$ 130,556	$ 250,727	$ 172,256
Cost of revenues:
Inventor royalties	29,724	26,028	43,727
Contingent legal fees	24,784	24,651	40,281
Litigation and licensing expenses - patents	39,335	21,591	13,005
Amortization of patents	53,658	39,019	9,745
Verdict insurance proceeds	0	0	(12,451)
Verdict insurance proceeds related costs	0	0	7,661
Marketing, general and administrative expenses (including non-cash stock compensation expense of $27,894 in 2013, $25,657 in 2012 and $13,579 in 2011)	59,229	54,083	35,693
Research, consulting and other expenses - business development	3,251	4,943	4,338
Other	3,506	0	0
Total operating costs and expenses	213,487	170,315	141,999
Operating income (loss)	(82,931)	80,412	30,257
Other income	0	500	0
Interest income	1,938	825	81
Write off of investment	0	(45)	0
Gain (loss) on investment	193	(343)	15
Total other income (expense)	2,131	937	96
Income (loss) from operations before benefit from (provision for) income taxes	(80,800)	81,349	30,353
Benefit from (provision for) income taxes	21,958	(22,060)	(8,708)
Net income (loss) including noncontrolling interests in operating subsidiaries	(58,842)	59,289	21,645
Net loss (income) attributable to noncontrolling interests in operating subsidiaries	2,408	164	(539)
Net income (loss) attributable to Acacia Research Corporation	(56,434)	59,453	21,106
Net Income (Loss) Available to Common Stockholders, Basic	(56,945)	57,564	20,265
Net Income (Loss) Available to Common Stockholders, Diluted	$ (56,945)	$ 57,577	$ 20,273
Basic income (loss) per common share	$ (1.18)	$ 1.22	$ 0.51
Diluted income (loss) per common share	$ (1.18)	$ 1.21	$ 0.50
Weighted-average number of shares outstanding, basic	48,155,832	47,251,061	39,743,433
Weighted-average number of shares outstanding, diluted	48,155,832	47,584,120	40,150,600
Common Stock, Dividends, Per Share, Cash Paid	$ 0.375	$ 0.000	$ 0.000