Acacia Research (ACTG) 10-K 2 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 25, 2015	Jun. 30, 2014
Entity Information [Line Items]
Entity Registrant Name	ACACIA RESEARCH CORP
Entity Central Index Key	934549
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		50,948,316
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$871,822,000

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$134,466	$126,685
Short-term investments	58,558	130,017
Accounts receivable	20,168	6,341
Deferred income tax	1,161	3,139
Prepaid expenses and other current assets	4,355	7,546
Total current assets	218,708	273,728
Furniture and equipment, net of accumulated depreciation and amortization	500	766
Patents, net of accumulated amortization	286,636	288,432
Goodwill	30,149	30,149
Other assets	355	318
Total assets	536,348	593,393
Current liabilities:
Accounts payable and accrued expenses	14,860	11,555
Accrued patent investment costs	16,700	4,000
Royalties and contingent legal fees payable	14,351	10,447
Total current liabilities	45,911	26,002
Deferred income taxes	1,161	4,874
Other liabilities	228	319
Total liabilities	47,300	31,195
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, par value $0.001 per share; 10,000,000 shares authorized; no shares issued or outstanding	0	0
Common stock, par value $0.001 per share; 100,000,000 shares authorized; 50,065,382 shares issued and outstanding as of December 31, 2014 and 49,385,057 shares issued and outstanding as of December 31, 2013	50	49
Treasury stock, at cost, 1,729,408 shares as of December 31, 2014 and December 31, 2013	-34,640	-34,640
Additional paid-in capital	646,595	653,314
Accumulated comprehensive loss	-353	-947
Accumulated deficit	-128,095	-62,066
Total Acacia Research Corporation stockholders’ equity	483,557	555,710
Noncontrolling interests in operating subsidiaries	5,491	6,488
Total stockholders’ equity	489,048	562,198
Total liabilities and stockholders' equity	$536,348	$593,393

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets Parentheticals (USD $)	Dec. 31, 2014	Dec. 31, 2013
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value per share	$0.00	$0.00
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	50,065,382	49,385,057
Common stock, shares outstanding	50,065,382	49,385,057
Treasury stock, shares	1,729,408	1,729,408

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Revenues	$130,876	$130,556	$250,727
Cost of revenues:
Inventor royalties	20,670	29,724	26,028
Contingent legal fees	23,563	24,784	24,651
Litigation and licensing expenses - patents	37,614	39,335	21,591
Amortization of patents	57,242	53,658	39,019
Marketing, general and administrative expenses (including non-cash stock compensation expense of $18,115 in 2014, $27,894 in 2013 and $25,657 in 2012)	48,554	59,229	54,083
Research, consulting and other expenses - business development	3,840	3,251	4,943
Other	1,548	3,506	0
Total operating costs and expenses	193,031	213,487	170,315
Operating income (loss)	-62,155	-82,931	80,412
Other income	0	0	500
Interest and other investment income (loss)	-595	2,131	482
Write off of investment	0	0	-45
Total other income (expense)	-595	2,131	937
Income (loss) from operations before (provision for) benefit from income taxes	-62,750	-80,800	81,349
(Provision for) benefit from income taxes	-3,912	21,958	-22,060
Net income (loss) including noncontrolling interests in operating subsidiaries	-66,662	-58,842	59,289
Net loss attributable to noncontrolling interests in operating subsidiaries	633	2,408	164
Net income (loss) attributable to Acacia Research Corporation	-66,029	-56,434	59,453
Net Income (Loss) Available to Common Stockholders, Basic	-66,755	-56,945	57,564
Net Income (Loss) Available to Common Stockholders, Diluted	($66,755)	($56,945)	$57,577
Basic income (loss) per common share	($1.37)	($1.18)	$1.22
Diluted income (loss) per common share	($1.37)	($1.18)	$1.21
Weighted-average number of shares outstanding, basic	48,658,088	48,155,832	47,251,061
Weighted-average number of shares outstanding, diluted	48,658,088	48,155,832	47,584,120
Common Stock, Dividends, Per Share, Cash Paid	$0.50	$0.38	$0

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations Parentheticals (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Non-cash stock compensation	$18,115	$27,894	$25,657

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income (loss) including noncontrolling interests in operating subsidiaries	($66,662)	($58,842)	$59,289
Other comprehensive income (loss):
Unrealized loss on short-term investments	-1,488	26	657
Unrealized gain on foreign currency translation	-128	0	7
Add: reclassification adjustment for losses included in net income	2,210	193	277
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	-66,068	-58,623	60,230
Net (income) loss attributable to noncontrolling interests in operating subsidiaries	-633	-2,408	-164
Comprehensive income	($65,435)	($56,215)	$60,394

Consolidated_Statements_of_Sto

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

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity Parentheticals (Additional Paid-in Capital [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Additional Paid-in Capital [Member]
Issuance costs	$0		$6,039

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income (loss) including noncontrolling interests in operating subsidiaries	($66,662)	($58,842)	$59,289
Adjustments to reconcile net income (loss) including noncontrolling interests in operating subsidiaries to net cash provided by (used in) operating activities:
Depreciation and amortization	57,546	53,894	39,168
Non-cash stock compensation	18,115	27,894	25,657
Excess tax benefits from stock-based compensation	0	1,398	-13,210
Provision for deferred income taxes	-1,736	-26,746	9,889
Other	-28	12	777
Changes in assets and liabilities:
Accounts receivable	-13,827	3,502	-6,928
Prepaid expenses and other assets	3,154	-5,300	-1,294
Accounts payable and accrued expenses / costs	3,718	2,740	2,255
Royalties and contingent legal fees payable	3,904	-2,061	-11,000
Net cash provided by (used in) operating activities	4,184	-3,509	104,603
Cash flows from investing activities:
Purchase of property and equipment	-109	-675	-268
Purchase of available-for-sale investments	-109,963	-279,693	-402,500
Sale of available-for-sale investments	182,115	239,370	322,236
Purchase of ADAPTIX, Inc., net of cash acquired	0	0	-150,000
Patent acquisition costs	-42,746	-25,061	-178,260
Net cash provided by (used in) investing activities	29,297	-66,059	-408,792
Cash flows from financing activities:
Payments of Dividends	-25,039	-18,633	0
Distributions to noncontrolling interests in operating subsidiary	-867	0	-312
Proceeds from the exercise of stock options	206	486	340
Repurchases of common stock	0	-7,926	-26,732
Contributions from noncontrolling interests in operating subsidiary, net of issuance costs	0	1,920	5,793
Excess tax benefits from stock-based compensation	0	-1,398	13,210
Proceeds from sale of common stock, net of issuance costs	0	0	218,961
Net cash provided by (used in) financing activities	-25,700	-25,551	211,260
Increase in cash and cash equivalents	7,781	-95,119	-92,929
Cash and cash equivalents, beginning	126,685	221,804	314,733
Cash and cash equivalents, ending	134,466	126,685	221,804
Patent acquisition costs included in accrued expenses	$16,700	$4,000	$0

Description_of_Business

Description of Business	12 Months Ended
	Dec. 31, 2014
DESCRIPTION OF BUSINESS [Abstract]
Description of Business	DESCRIPTION OF BUSINESS
	Description of Business. As used herein, “Acacia” and the “Company” refer to Acacia Research Corporation and/or its wholly and majority-owned and controlled operating subsidiaries, and/or where applicable, its management. All patent investment, prosecution, licensing and enforcement activities are conducted solely by certain of Acacia’s wholly and majority-owned and controlled operating subsidiaries.
	Acacia’s operating subsidiaries invest in, license and enforce patented technologies. Acacia’s operating subsidiaries partner with inventors and patent owners, applying their legal and technology expertise to patent assets to unlock the financial value in their patented inventions. Acacia is an intermediary in the patent marketplace, bridging the gap between invention and application, facilitating efficiency and delivering monetary rewards to patent owners.
	Acacia’s operating subsidiaries generate revenues and related cash flows from the granting of intellectual property rights for the use of patented technologies that its operating subsidiaries control or own. Acacia’s operating subsidiaries assist patent owners with the prosecution and development of their patent portfolios, the protection of their patented inventions from unauthorized use, the generation of licensing revenue from users of their patented technologies and, where necessary, with the enforcement against unauthorized users of their patented technologies through the filing of patent infringement litigation.
	Acacia’s operating subsidiaries are principals in the licensing and enforcement effort, obtaining control of the rights in the patent portfolio, or control of the patent portfolio outright. Acacia’s operating subsidiaries own or control the rights to multiple patent portfolios, which include U.S. patents and certain foreign counterparts, covering technologies used in a wide variety of industries.
	In January 2012, a wholly owned operating subsidiary of Acacia acquired ADAPTIX, Inc. (“ADAPTIX”), a pioneer in the development of 4G technologies for wireless systems, for cash consideration of $150,000,000, net of cash acquired, as described at Note 7 to these consolidated financial statements.
	Acacia was incorporated on January 25, 1993 under the laws of the State of California. In December 1999, Acacia changed its state of incorporation from California to Delaware.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Accounting Principles and Fiscal Year End.  The consolidated financial statements and accompanying notes are prepared on the accrual basis of accounting in accordance with generally accepted accounting principles in the United States of America.
	Principles of Consolidation.  The accompanying consolidated financial statements include the accounts of Acacia and its wholly and majority-owned and controlled subsidiaries. Material intercompany transactions and balances have been eliminated in consolidation.
	Noncontrolling interests in Acacia’s majority-owned and controlled operating subsidiaries (“noncontrolling interests”) are separately presented as a component of stockholders’ equity. Consolidated net income or (loss) is adjusted to include the net (income) or loss attributed to noncontrolling interests in the consolidated statements of operations. Refer to the accompanying consolidated statements of stockholders’ equity for total noncontrolling interests.
	In August 2010, a wholly owned subsidiary of Acacia became the general partner of the Acacia Intellectual Property Fund, L.P. (the “Acacia IP Fund”), which was formed in August 2010. The Acacia IP Fund is included in the Company’s consolidated financial statements since 2010, as Acacia’s wholly owned subsidiary, as the general partner, has the ability to control the operations and activities of the Acacia IP Fund. Refer to Note 11 to these consolidated financial statements.
	Revenue Recognition.  Revenue is recognized when (i) persuasive evidence of an arrangement exists, (ii) all obligations have been substantially performed pursuant to the terms of the arrangement, (iii) amounts are fixed or determinable, and (iv) the collectibility of amounts is reasonably assured.
	In general, revenue arrangements provide for the payment of contractually determined fees in consideration for the grant of certain intellectual property rights for patented technologies owned or controlled by Acacia’s operating subsidiaries. These rights typically include some combination of the following: (i) the grant of a non-exclusive, retroactive and future license to manufacture and/or sell products covered by patented technologies owned or controlled by Acacia’s operating subsidiaries, (ii) a covenant-not-to-sue, (iii) the release of the licensee from certain claims, and (iv) the dismissal of any pending litigation. The intellectual property rights granted may be perpetual in nature, extending until the expiration of the related patents, or can be granted for a defined, relatively short period of time, with the licensee possessing the right to renew the agreement at the end of each contractual term for an additional minimum upfront payment. Pursuant to the terms of these agreements, Acacia’s operating subsidiaries have no further obligation with respect to the grant of the non-exclusive retroactive and future licenses, covenants-not-to-sue, releases, and other deliverables, including no express or implied obligation on Acacia’s operating subsidiaries’ part to maintain or upgrade the technology, or provide future support or services. Generally, the agreements provide for the grant of the licenses, covenants-not-to-sue, releases, and other significant deliverables upon execution of the agreement, or upon receipt of the minimum upfront payment for term agreement renewals. As such, the earnings process is complete and revenue is recognized upon the execution of the agreement, when collectibility is reasonably assured, or upon receipt of the minimum upfront fee for term agreement renewals, and when all other revenue recognition criteria have been met.
	For the periods presented herein, the majority of the revenue agreements executed by the Company provided for the payment of one-time, paid-up license fees in consideration for the grant of certain intellectual property rights for patented technology rights owned by our operating subsidiaries. These rights were primarily granted on a perpetual basis, extending until the expiration of the underlying patents.
	Certain of the Company’s revenue arrangements provide for future royalties or additional required payments based on future licensee activities. Additional royalties are recognized in revenue upon resolution of the related contingency provided that all revenue recognition criteria, as described above, have been met. Amounts of additional royalties due under these license agreements, if any, cannot be reasonably estimated by management.
	Certain of the Company’s revenue arrangements provide for the calculation of fees based on a licensee’s actual quarterly sales or actual per unit activity, applied to a contractual royalty rate. Licensees that pay fees on a quarterly basis generally report actual quarterly sales or actual per unit activity information and related quarterly fees due within 30 days to 45 days after the end of the quarter in which such sales or activity takes place. The amount of fees due under these revenue arrangements each quarter cannot be reasonably estimated by management. Consequently, Acacia’s operating subsidiaries recognize revenue from these revenue arrangements on a three-month lag basis, in the quarter following the quarter of sales or per unit activity, provided amounts are fixed or determinable and collectibility is reasonably assured. The lag method described above allows for the receipt of licensee royalty reports prior to the recognition of revenue.
	Amounts related to revenue arrangements that do not meet the revenue recognition criteria described above are deferred until the revenue recognition criteria are met.
	Acacia assesses the collectibility of fees receivable based on a number of factors, including past transaction history and credit-worthiness of licensees. If it is determined that collection is not reasonably assured, the fee is recognized when collectibility becomes reasonably assured, assuming all other revenue recognition criteria have been met, which is generally upon receipt of cash.
	Cost of Revenues.  Cost of revenues include the costs and expenses incurred in connection with Acacia’s patent licensing and enforcement activities, including inventor royalties paid to original patent owners, contingent legal fees paid to external patent counsel, other patent-related legal expenses paid to external patent counsel, licensing and enforcement related research, consulting and other expenses paid to third-parties and the amortization of patent-related investment costs. These costs are included under the caption “Cost of revenues” in the accompanying consolidated statements of operations.
	Inventor Royalties and Contingent Legal Expenses. Inventor royalties are expensed in the consolidated statements of operations in the period that the related revenues are recognized. In certain instances, pursuant to the terms of the underlying inventor agreements, upfront advances paid to patent owners by Acacia’s operating subsidiaries are recoverable from future net revenues. Patent costs that are recoverable from future net revenues are amortized over the estimated economic useful life of the related patents, or as the prepaid royalties are earned by the inventor, as appropriate, and the related expense is included in amortization expense in the consolidated statements of operations. Any unamortized patent portfolio investment costs recovered from net revenues are expensed in the period recovered, and included in amortization expense in the consolidated statements of operations. Refer to Note 11 for additional information.
	Contingent legal fees are expensed in the consolidated statements of operations in the period that the related revenues are recognized. In instances where there are no recoveries from potential infringers, no contingent legal fees are paid; however, Acacia’s operating subsidiaries may be liable for certain out of pocket legal costs incurred pursuant to the underlying legal services agreement.
	Fair Value Measurements. U.S. generally accepted accounting principles define fair value as the price that would be received for an asset or the exit price that would be paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants on the measurement date, and also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs, where available. The three-level hierarchy of valuation techniques established to measure fair value is defined as follows:
		●	Level 1 -	Observable Inputs:  Quoted prices in active markets for identical investments;
		●	Level 2 -	Pricing Models with Significant Observable Inputs:  Other significant observable inputs, including quoted prices for similar investments, interest rates, credit risk, etc.; and
		●	Level 3 -	Unobservable Inputs:  Significant unobservable inputs, including the entity’s own assumptions in determining the fair value of investments.
	Whenever possible, the Company is required to use observable market inputs (Level 1 - quoted market prices) when measuring fair value. Acacia has not elected the fair value option for recording non-financial assets and liabilities, and therefore no fair value measurements are performed on a recurring basis.
	Cash and Cash Equivalents.  Acacia considers all highly liquid, short-term investments with original maturities of three months or less when purchased to be cash equivalents. For the periods presented, Acacia’s cash equivalents are comprised of investments in AAA rated money market funds that invest in first-tier only securities, which primarily includes: domestic commercial paper, securities issued or guaranteed by the U.S. government or its agencies, U.S. bank obligations, and fully collateralized repurchase agreements. Acacia’s cash equivalents are measured at fair value using quoted prices that represent Level 1 inputs.
	Investments in Marketable Securities.  Investments in securities with original maturities of greater than three months and less than one year and other investments representing amounts that are available for current operations are classified as short-term investments, unless there are indications that such investments may not be readily sold in the short term. The fair values of these investments approximate their carrying values. At December 31, 2014 and 2013, all of Acacia’s investments were classified as available-for-sale, which are reported at fair value on a recurring basis using significant observable inputs (Level 1), with related unrealized gains and losses in the value of such securities recorded as a separate component of other comprehensive income (loss) in stockholders’ equity until realized. Realized and unrealized gains and losses are recorded based on the specific identification method. Interest on all securities is included in interest and other investment income (loss).
	Impairment of Marketable Securities. Acacia evaluates its investments in marketable securities for potential impairment, employing a systematic methodology on a quarterly basis that considers available quantitative and qualitative evidence. If the cost or carrying value of an investment exceeds its estimated fair value, the Company evaluates, among other factors, general market conditions, credit quality of instrument issuers, the duration and extent to which the fair value is less than cost, and the Company’s intent and ability to hold, or plans or ability to sell. Fair value is estimated based on publicly available market information or other estimates determined by management. Investments are considered to be impaired when a decline in fair value is estimated to be other-than-temporary. Acacia reviews impairments associated with its investments in marketable securities and determines the classification of any impairment as temporary or other-than-temporary. An impairment is deemed other-than-temporary unless (a) Acacia has the ability and intent to hold an investment for a period of time sufficient for recovery of its carrying amount and (b) positive evidence indicating that the investment’s carrying amount is recoverable within a reasonable period of time outweighs any evidence to the contrary. All available evidence, both positive and negative, is considered to determine whether, based on the weight of such evidence, the carrying amount of the investment is recoverable within a reasonable period of time. For investments classified as available-for-sale, unrealized losses that are other-than-temporary are recognized in the consolidated statements of operations.
	Concentration of Credit Risks.  Financial instruments that potentially subject Acacia to concentrations of credit risk are cash equivalents, investments and accounts receivable. Acacia places its cash equivalents and investments primarily in highly rated money market funds and investment grade marketable securities. Cash equivalents are also invested in deposits with certain financial institutions and may, at times, exceed federally insured limits. Acacia has not experienced any significant losses on its deposits of cash and cash equivalents.
	Two licensees individually accounted for 22% and 22%, respectively, of revenues recognized during the year ended December 31, 2014. Two licensees individually accounted for 38% and 16%, respectively, of revenues recognized during the year ended December 31, 2013. Four licensees individually accounted for 21%, 14%, 10% and 10%, respectively, of revenues recognized during the year ended December 31, 2012. Three licensees individually represented approximately 30%, 17% and 15%, respectively, of accounts receivable at December 31, 2014. Two licensees individually represented approximately 60% and 22% of accounts receivable at December 31, 2013. For 2014, 2013 and 2012, 43%, 24% and 43%, respectively, of revenues were attributable to licensees domiciled in foreign jurisdictions, based on the jurisdiction of the entity obligated to satisfy payment obligations pursuant to the applicable revenue arrangement. The Company does not have any material foreign operations.
	Acacia performs credit evaluations of its licensees with significant receivable balances, if any, and has not experienced any significant credit losses. Accounts receivable are recorded at the executed contract amount and generally do not bear interest. Collateral is not required. An allowance for doubtful accounts may be established to reflect the Company’s best estimate of probable losses inherent in the accounts receivable balance, and is reflected as a contra-asset account on the balance sheet and a charge to operating expenses in the statement of operations for the applicable period. The allowance is determined based on known troubled accounts, historical experience, and other currently available evidence. There was no allowance for doubtful accounts established for the periods presented.
	Furniture and Equipment.  Furniture and equipment are recorded at cost. Major additions and improvements that materially extend useful lives of furniture and equipment are capitalized. Maintenance and repairs are charged against the results of operations as incurred. When these assets are sold or otherwise disposed of, the asset and related depreciation are relieved, and any gain or loss is included in the consolidated statements of operations for the period of sale or disposal. Depreciation and amortization is computed on a straight-line basis over the following estimated useful lives of the assets:
	Furniture and fixtures	3 to 5 years
	Computer hardware and software	3 to 5 years
	Leasehold improvements	2 to 5 years (Lesser of lease term or useful life of improvement)
	Rental payments on operating leases are charged to expense in the consolidated statements of operations on a straight-line basis over the lease term.
	Patents.  Patents include the cost of patents or patent rights (hereinafter, collectively “patents”) acquired from third-parties or obtained in connection with business combinations. Patent costs are amortized utilizing the straight-line method over their remaining economic useful lives, ranging from one to ten years. Certain patent application and prosecution costs incurred to secure additional patent claims, that based on management’s estimates are deemed to be recoverable, are capitalized and amortized over the remaining estimated economic useful life of the related patent portfolio.
	Goodwill. Goodwill is tested for impairment at the reporting unit level (operating segment or one level below an operating segment) on an annual basis (December 31) and between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value. Acacia considers its market capitalization and the carrying value of its assets and liabilities, including goodwill, when performing its goodwill impairment test. When conducting its annual goodwill impairment assessment, the Company initially performs a qualitative evaluation of whether it is more likely than not that goodwill is impaired. If it is determined by a qualitative evaluation that it is more likely than not that goodwill is impaired, the Company then applies a two-step impairment test. The two-step impairment test first compares the fair value of the Company’s reporting unit to its carrying or book value. If the fair value of the reporting unit exceeds its carrying value, goodwill is not impaired and the Company is not required to perform further testing. If the carrying value of the reporting unit exceeds its fair value, the Company determines the implied fair value of the reporting unit’s goodwill and if the carrying value of the reporting unit’s goodwill exceeds its implied fair value, then an impairment loss equal to the difference is recorded in the consolidated statement of operations.
	Impairment of Long-lived Assets. Acacia reviews long-lived assets and intangible assets for potential impairment annually (quarterly for patents) and when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. In the event the expected undiscounted future cash flows resulting from the use of the asset is less than the carrying amount of the asset, an impairment loss is recorded equal to the excess of the asset’s carrying value over its fair value. If an asset is determined to be impaired, the loss is measured based on quoted market prices in active markets, if available. If quoted market prices are not available, the estimate of fair value is based on various valuation techniques, including a discounted value of estimated future cash flows.
	Fair value is generally estimated using the “Income Approach,” focusing on the estimated future net income-producing capability of the patent portfolios over the estimated remaining economic useful life. Estimates of future after-tax cash flows are converted to present value through “discounting,” including an estimated rate of return that accounts for both the time value of money and investment risk factors. Estimated cash inflows are typically based on estimates of reasonable royalty rates for the applicable technology, applied to estimated market share data. Estimated cash outflows are based on existing contractual obligations, such as contingent legal fee and inventor royalty obligations, applied to estimated license fee revenues, in addition to other estimates of out-of-pocket expenses associated with a specific patent portfolio’s licensing and enforcement program. The analysis also contemplates consideration of current information about the patent portfolio including, status and stage of litigation, periodic results of the litigation process, strength of the patent portfolio, technology coverage and other pertinent information that could impact future net cash flows.
	Fair Value of Financial Instruments.  The carrying value of cash and cash equivalents, investments, accounts receivables, accounts payable and accrued expenses approximates their fair values due to their short-term maturities.
	Contingent Liabilities. The Company, from time to time, is involved in certain legal proceedings. Based upon consultation with outside counsel handling its defense in these matters and the Company’s analysis of potential outcomes, if the Company determines that a loss arising from such matters is probable and can be reasonably estimated, an estimate of the contingent liability is recorded in its consolidated financial statements. If only a range of estimated loss can be determined, an amount within the range that, based on estimates, assumptions and judgments, reflects the most likely outcome, is recorded as a contingent liability in the consolidated financial statements. In situations where none of the estimates within the estimated range is a better estimate of probable loss than any other amount, the Company records the low end of the range. Any such accrual would be charged to expense in the appropriate period. Litigation expenses for these types of contingencies are recognized in the period in which the litigation services were provided.
	Stock-Based Compensation. The compensation cost for all stock-based awards is measured at the grant date, based on the fair value of the award, and is recognized as an expense on a straight-line basis over the employee’s requisite service period (generally the vesting period of the equity award) which is generally two to four years. The fair value of restricted stock and restricted stock unit awards is determined by the product of the number of shares or units granted and the grant date market price of the underlying common stock. The fair value of each option award is estimated on the date of grant using a Black-Scholes option valuation model. Stock-based compensation expense is recorded only for those awards expected to vest using an estimated forfeiture rate. Refer to Note 10 to these notes to consolidated financial statements for information on stock-based awards granted for the periods presented.
	Income Taxes.  Income taxes are accounted for using an asset and liability approach that requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in Acacia’s consolidated financial statements or consolidated income tax returns. A valuation allowance is established to reduce deferred tax assets if all, or some portion, of such assets will more than likely not be realized, or if it is determined that there is uncertainty regarding future realizability of such assets.
	Under U.S. generally accepted accounting principles, a tax position is a position in a previously filed tax return or a position expected to be taken in a future tax filing that is reflected in measuring current or deferred income tax assets and liabilities. Tax positions are recognized only when it is more likely than not (likelihood of greater than 50%), based on technical merits, that the position will be sustained upon examination. Tax positions that meet the more likely than not threshold are measured using a probability weighted approach as the largest amount of tax benefit that is greater than 50% likely of being realized upon settlement.
	If a deduction reported on a tax return for an equity-based incentive award exceeds the cumulative compensation cost for those instruments recognized for financial reporting purposes, any resulting realized tax benefit that exceeds the previously calculated deferred tax asset for those instruments is considered an excess tax benefit, and is recognized as additional paid-in capital. If the tax deduction is less than the cumulative book compensation cost, the tax effect of the resulting difference is charged first to APIC, to the extent of the available pool of windfall tax benefits, with any remainder recognized in income tax expense.
	Segment Reporting.  Acacia uses the management approach, which designates the internal organization that is used by management for making operating decisions and assessing performance as the basis of Acacia’s reportable segments. Acacia’s patent licensing and enforcement business constitutes its single reportable segment.
	Use of Estimates.  The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. Acacia believes that, of the significant accounting policies described herein, the accounting policies associated with revenue recognition, stock-based compensation expense, impairment of marketable securities and intangible assets, the determination of the economic useful life of amortizable intangible assets, income taxes and valuation allowances against net deferred tax assets and the application of the acquisition method of accounting for business combinations, require its most difficult, subjective or complex judgments.
	Income (Loss) Per Share.  The Company computes net income (loss) attributable to common stockholders using the two-class method required for capital structures that include participating securities. Under the two-class method, securities that participate in non-forfeitable dividends, such as the Company’s outstanding unvested restricted stock, are considered “participating securities.”
	In applying the two-class method, (i) basic net income (loss) per share is computed by dividing net income (loss) (less any dividends paid on participating securities) by the weighted average number of shares of common stock and participating securities outstanding for the period and (ii) diluted earnings per share may include the additional effect of other securities, if dilutive, in which case the dilutive effect of such securities is calculated by applying the two-class method and the treasury stock method to the assumed exercise or vesting of potentially dilutive common shares. The method yielding the more dilutive result is ultimately reported for the applicable period. Potentially dilutive common stock equivalents primarily consist of employee stock options, and restricted stock units for calculations utilizing the two-class method, and also include unvested restricted stock, when utilizing the treasury method.
	The following table presents the weighted-average number of common shares outstanding used in the calculation of basic and diluted income per share:
			2014			2013			2012
	Numerator (in thousands):
	Basic
	Net income (loss)		$	(66,029	)	$	(56,434	)	$	59,453
	Undistributed earnings allocated to participating securities		—			—			(1,889		)
	Total dividends paid		(25,039		)	(18,633		)	—
	Dividends attributable to common stockholders		24,313			18,122			—
	Net income (loss) attributable to common stockholders – basic		$	(66,755	)	$	(56,945	)	$	57,564
	Diluted
	Net income (loss)		$	(66,029	)	$	(56,434	)	$	59,453
	Undistributed earnings allocated to participating securities		—			—			(1,876		)
	Total dividends paid		(25,039		)	(18,633		)	—
	Dividends attributable to common stockholders		24,313			18,122			—
	Net income (loss) attributable to common stockholders – diluted		$	(66,755	)	$	(56,945	)	$	57,577
	Denominator:
	Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – basic		48,658,088			48,155,832			47,251,061
	Effect of potentially dilutive securities:
	Common stock options and restricted stock units		—			—			333,059
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – diluted		48,658,088			48,155,832			47,584,120
Basic net income (loss) per common share		$	(1.37	)	$	(1.18	)	$	1.22
Diluted net income (loss) per common share		$	(1.37	)	$	(1.18	)	$	1.21
Anti-dilutive equity-based incentive awards excluded from the computation of diluted income (loss) per share		27,760			27,760			30,812
Revision of Prior Period Earnings (Loss) Per Share - Two-Class Method. In connection with the preparation of the Company’s Quarterly Report on Form 10-Q as of and for the three and nine months ended September 30, 2013, the Company determined that its basic and diluted net income (loss) per share calculations should have been prepared using the “two-class method.” Pursuant to guidance set forth in Staff Accounting Bulletin (“SAB”) No. 99, “Materiality,” the Company concluded that the errors were not material to any of its prior period financial statements. Although the errors were immaterial to prior periods, the prior period financial statements presented herein were revised, in accordance with SAB No. 108, “Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements.” The impact of the revision for the comparable prior period earnings (loss) per share calculations using the two-class method were as follows:
		2012
Numerator:
Net income attributable to common stockholders – basic and diluted - As Reported		$	59,453
Net income attributable to common stockholders – basic - As Adjusted		$	57,564
Net income attributable to common stockholders – diluted - As Adjusted		$	57,577
Denominator:
Weighted-average shares used in computing net income per share attributable to common stockholders – basic - As Reported		47,251,061
Weighted-average shares used in computing net income per share attributable to common stockholders – basic - As Adjusted		47,251,061
Weighted-average shares used in computing net income per share attributable to common stockholders – diluted - As Reported		48,060,647
Weighted-average shares used in computing net income per share attributable to common stockholders – diluted - As Adjusted		47,584,120
Basic net income per common share - As Reported		$	1.26
Basic net income per common share - As Adjusted		$	1.22
Diluted net income per common share - As Reported		$	1.24
Diluted net income per common share - As Adjusted		$	1.21
Treasury Stock. Repurchases of the Company’s outstanding common stock are accounted for using the cost method. The applicable par value is deducted from the appropriate capital stock account on the formal or constructive retirement of treasury stock. Any excess of the cost of treasury stock over its par value is charged to additional paid-in capital, and reflected as Treasury Stock on the consolidated balance sheets.
Recent Accounting Pronouncements - Not Yet Adopted. In June 2014, the Financial Accounting Standards Board (the “FASB”) issued a new accounting standard which requires that a performance target that affects vesting and could be achieved after the requisite service period shall be treated as a performance condition. Adoption of this standard is required for annual periods beginning after December 15, 2015. Early adoption is permitted. The Company is currently evaluating the impact the pronouncement will have on its consolidated financial statements and related disclosures.
In May 2014, the FASB issued a new accounting standards update addressing revenue from contracts with customers, which clarifies existing accounting literature relating to how and when a company recognizes revenue.  Under the standard, a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods and services.  The amendments for this standard update are effective for interim and annual reporting periods beginning after December 15, 2016, and are to be applied
retrospectively or the cumulative effect as of the date of adoption, with early application not permitted.  The Company is currently evaluating the impact and method of adoption the pronouncement will have on its consolidated financial statements and related disclosures.
In August 2014, the FASB issued a new accounting standard which requires management to assess an entity’s ability to continue as a going concern every reporting period including interim periods, and to provide related footnote disclosure in certain circumstances. Adoption of this standard is required for annual periods beginning after December 15, 2016 and are to be applied retrospectively or the cumulative effect as of the date of adoption. Early adoption is permitted. The Company is currently evaluating the impact the pronouncement will have on its consolidated financial statements and related disclosures.
Recently Adopted Accounting Pronouncements - Adopted Effective January 1, 2014. In July 2013, the FASB issued a new accounting standard addressing when unrecognized tax benefits should be presented as reductions to deferred tax assets for net operating loss carryforwards in the financial statements. This standard was adopted effective January 1, 2014. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and related disclosures.
In March 2013, the FASB issued a new accounting standard addressing the accounting for the cumulative translation adjustment when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity. This standard was adopted effective January 1, 2014. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and related disclosures.

Shortterm_Investments

Short-term Investments	12 Months Ended
	Dec. 31, 2014
Short-term Investments [Abstract]
Short-Term Investments	SHORT-TERM INVESTMENTS
	Short-term marketable securities for the periods presented were comprised of the following (in thousands):
		December 31, 2014
	Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	U.S. government fixed income securities	$	58,819	$	2	$	(263	)	$	58,558
	Total short-term investments	$	58,819	$	2	$	(263	)	$	58,558
		December 31, 2013
	Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	U.S. government fixed income securities	$	130,971	$	21	$	(975	)	$	130,017
	Total short-term investments	$	130,971	$	21	$	(975	)	$	130,017
	Short-term investments at December 31, 2014 and 2013 were comprised of investments in highly liquid, AAA, U.S. government fixed income securities with maturity dates in 2015, and ranging from 2014 to 2015, respectively. Short-term marketable securities in unrealized loss positions at December 31, 2014 and 2013 have been in continuous unrealized loss positions for less than one year.
	U.S. government fixed income securities. The gross unrealized loss can be primarily attributed to a combination of market conditions as well as the demand for and duration of the U.S. government fixed income securities. The Company has the ability to hold these securities until maturity, currently has no intent to sell, there is no requirement to sell and the Company believes that it can recover the amortized cost of these investments. The Company has found no evidence of impairment due to credit losses in its portfolio. Therefore, these unrealized losses were recorded in other comprehensive income (loss). However, the Company cannot provide any assurance that its portfolio of short-term marketable securities will not be impacted by adverse conditions in the financial markets, which may require the Company in the future to record an impairment charge for credit losses which could adversely impact its financial results.
	For the year ended December 31, 2014, proceeds from the sale of short-term marketable securities classified as available-for-sale were $182,115,000 and gross realized losses were $2,188,000. Gross realized losses are recorded in the statements of operations in interest and other investment income (loss). For the year ended December 31, 2013, proceeds from the sale of short-term marketable securities classified as available-for-sale were $239,370,000, gross realized gains were $1,174,000 and gross realized losses were $981,000. For the year ended December 31, 2012, proceeds from the sale of short-term marketable securities classified as available-for-sale were $319,811,000, gross realized gains were $31,000 and gross realized losses were $555,000.

Furniture_and_Equipment

Furniture and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and Equipment	FURNITURE AND EQUIPMENT
	Furniture and equipment consists of the following at December 31, 2014 and 2013 (in thousands):
		2014			2013
	Furniture and fixtures	$	761		$	783
	Computer hardware and software	650			687
	Leasehold improvements	144			306
		1,555			1,776
	Less:  accumulated depreciation and amortization	(1,055		)	(1,010		)
		$	500		$	766
	Depreciation expense was $304,000, $236,000 and $149,000 for the years ended December 31, 2014, 2013 and 2012, respectively. In 2014 and 2013, the Company retired $330,000 and $130,000, respectively, of items held in furniture and equipment and recorded a $71,000 and $12,000, respectively, loss on disposal.

Accounts_Payable_and_Accrued_E

Accounts Payable and Accrued Expenses	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accounts Payable and Accrued Expenses / Costs	ACCOUNTS PAYABLE AND ACCRUED EXPENSES
	Accounts payable and accrued expenses consist of the following at December 31, 2014 and 2013 (in thousands):
		2014		2013
	Accounts payable	$	121	$	128
	Payroll and other employee benefits	1,481		1,039
	Accrued vacation	806		813
	Accrued legal expenses - patent	8,410		5,900
	Accrued attorney's fees	1,548		—
	Accrued consulting and other professional fees	1,530		2,948
	Accrued distribution to noncontrolling interests	—		504
	Other accrued liabilities	964		223
		$	14,860	$	11,555

Patents

Patents	12 Months Ended
	Dec. 31, 2013
Patents [Abstract]
Patents
	Acacia’s only identifiable intangible assets are patents and patent rights, with estimated remaining economic useful lives ranging from one to nine years. For all periods presented, all of Acacia’s identifiable intangible assets were subject to amortization. The gross carrying amounts and accumulated amortization related to investments in intangible assets as of December 31, 2014 and 2013 are as follows (in thousands):
		2014			2013
	Gross carrying amount - patents	$	453,201		$	400,755
	Accumulated amortization - patents	(166,565		)	(112,323		)
	Patents, net	$	286,636		$	288,432
	The weighted-average remaining estimated economic useful life of Acacia’s patents and patent rights is 6 years. Scheduled annual aggregate amortization expense is estimated to be $52,019,000 in 2015, $49,332,000 in 2016, $48,245,000 in 2017, $44,117,000 in 2018, $38,679,000 in 2019 and $54,244,000 thereafter.
	For the years ended December 31, 2014, 2013 and 2012, Acacia paid patent investment costs totaling $42,746,000, $25,061,000 and $178,260,000 (excluding the investment in ADAPTIX), respectively. The patents have estimated economic useful lives ranging from three to ten years. Included in net additions to capitalized patent costs during the years ended December 31, 2014 and 2013 are accrued patent investment costs totaling $16,700,000 and $4,000,000, respectively, which are amortized over the estimated economic useful life of the related patents.
	Refer to Note 7 to these consolidated financial statements for additions to patents and goodwill in connection with Acacia’s acquisition of ADAPTIX and the related application of the acquisition method of accounting.
	During the periods presented, certain operating subsidiaries recovered up-front patent portfolio advances from applicable net licensing proceeds prior to the scheduled amortization of such up-front patent portfolio advances, resulting in the acceleration of amortization expense for the applicable patent-related assets. For the years ended December 31, 2014, 2013 and 2012, accelerated amortization expense related to the recovery of up-front patent portfolio advances totaled $1,247,000, $592,000 and $10,574,000, respectively.
	For the years ended December 31, 2014, 2013 and 2012, pursuant to the terms of the respective inventor agreements, certain Acacia operating subsidiaries elected to terminate or sell their rights to patent portfolios, resulting in the acceleration of amortization expense for the patent-related assets totaling $2,702,000, $1,747,000 and $3,034,000, respectively. Included in amortization of patents for the year ended December 31, 2014 and 2013 are patent impairment charges totaling $3,497,000 and $4,619,000, respectfully. There was no impairment charge in 2012. The impairment charges related to partial impairment of a portfolio due to a reduction in expected estimated future net cash flows (2014 only) and certain patent portfolios that management determined it would no longer allocate future resources to in connection with the licensing and enforcement of such portfolios, due primarily to potential prior art related complexities in two of the programs (2013 only) and/or the overall determination that future resources would be allocated to other licensing and enforcement programs with higher potential return profiles. The impairment charges consisted of the excess of the asset’s carrying value over its estimated fair value as of December 31, 2014 and 2013.
	For the years ended December 31, 2014, 2013 and 2012, capitalized patent costs and accumulated amortization, and sales proceeds and other costs, related to patent-related sales and disposals are as follows (in thousands):
		2014			2013			2012
	Capitalized patent costs	$	3,000		$	3,500		$	5,500
	Accumulated amortization	298			1,753			2,466
	Sales proceeds	3,500			1,000			2,792

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	ACQUISITION
	On January 12, 2012 (the “Acquisition Date”), pursuant to the terms and conditions of the Agreement and Plan of Merger dated as of November 22, 2011 (the “Merger Agreement”) among Acacia Research Group LLC (“ARG”), a wholly-owned subsidiary of Acacia, Apollo Patent Corp., a newly-formed, wholly-owned subsidiary of ARG (“Merger Sub”), ADAPTIX, a Delaware corporation, and Baker Communications Fund II (QP), L.P. solely in its capacity as shareholder representative, ARG completed its acquisition of ADAPTIX, which held no material assets other than its portfolio of patents and $10,000,000 in cash, through a merger of Merger Sub with and into ADAPTIX, with ADAPTIX as the surviving corporation (the “Merger”). Upon completion of the Merger, the separate corporate existence of Merger Sub ceased and ADAPTIX became a wholly-owned subsidiary of ARG.
	ADAPTIX, a pioneer in the development of 4G technologies for wireless systems, is a technology company recognized in the industry as one of the first developers of 4G wireless systems. With patents filed as early as 2000, ADAPTIX’s research and development efforts have resulted in a significant intellectual property portfolio focused on 4G technologies. With its growing portfolio of 230 issued and pending patents in 13 countries, ADAPTIX’s innovations extend across a broad range of 4G technologies including OFDMA and MIMO.
	The Merger was being accounted for in accordance with the acquisition method of accounting under FASB ASC Topic 805, “Business Combinations” (“Topic 805”). Topic 805 requires, among other things, that identifiable assets acquired and liabilities assumed be recognized at their fair values as of the Acquisition Date. Under the acquisition method of accounting, the purchase consideration is allocated to the assets acquired, including tangible assets, patents and other identifiable intangible assets and liabilities assumed, based on their estimated fair market values on the date of acquisition. Any excess purchase price after the initial allocation to identifiable net tangible and identifiable intangible assets is assigned to goodwill. Amounts attributable to patents are amortized using the straight-line method over the estimated economic useful life of the underlying patents.
	The total consideration paid by ARG in connection with the Merger was approximately $160,000,000, in cash. Based on the total purchase consideration and the estimate of the assets acquired and the liabilities assumed by ARG as of the Acquisition Date, the purchase price allocation was as follows ($ amounts in thousands):
						Amortization Period		Annual Amortization
	Assets Acquired and Liabilities Assumed:
	Fair value of net tangible assets acquired		$	10,000
	Intangible assets acquired - patents		150,000			10 years		$	15,000
	Goodwill		30,149
	Net deferred income tax liability		(30,149		)
	Total		$	160,000
	Amounts attributable to the patents acquired are being amortized using the straight-line method over an estimated weighted average economic useful life of the underlying patents, which was estimated to be approximately 10 years. Goodwill is calculated as the residual after recording the identifiable net assets acquired and associated net deferred tax assets and liabilities.
	Management is responsible for determining the fair value of the tangible and identifiable intangible assets acquired and liabilities assumed as of the Acquisition Date. Management considered a number of factors, including reference to an analysis under Topic 805 solely for the purpose of allocating the purchase price to the assets acquired and liabilities assumed. The analysis included a discounted cash flow which estimated future net cash flows resulting from the licensing and enforcement of the patent portfolio based on information as of the date of acquisition, considering assumptions and estimates related to potential infringers of the patents, applicable industries, usage of the underlying patented technologies, estimated license fee revenues, contingent legal fee arrangements, other estimated costs, tax implications and other factors. A discount rate consistent with the risks associated with achieving the estimated net cash flows was used to estimate the present value of estimated net cash flows.
	The Merger was treated for tax purposes as a nontaxable transaction and as such, the historical tax bases of the acquired assets and assumed liabilities, net operating losses, and other tax attributes of ADAPTIX will carryover. As a result, no new tax goodwill will be created in connection with the Merger as there is no step-up to fair value of the underlying tax bases of the acquired net assets. Acquisition accounting includes the establishment of a net deferred tax asset or liability resulting from book tax basis differences related to assets acquired and liabilities assumed on the date of acquisition. Acquisition date deferred tax assets primarily relate to certain net operating loss carryforwards of ADAPTIX. Acquisition date deferred tax liabilities relate to specifically identified non-goodwill intangibles acquired. The estimated net deferred tax liability was determined as follows ($ amounts in thousands):
			Book Basis			Tax Basis				Difference
	Intangible assets acquired - patents		$	150,000		$	—			$	(150,000	)
	Estimated acquired deferred tax assets (including net operating loss carryforwards) - ADAPTIX		—			63,860				63,860
	Net deferred tax liability - pretax									(86,140		)
	Estimated tax rate									35		%
	Estimated net deferred tax liability									$	(30,149	)
	The following unaudited pro forma combined results of operations for periods presented are provided for illustrative purposes only and assume the acquisition occurred as of January 1, 2012. The unaudited pro forma combined financial results do not purport to be indicative of the results of operations for future periods or the results that actually would have been realized had the entities been a single entity during these periods. The unaudited pro forma combined results are presented in thousands, except share and per share information.
		2012
	Revenues	$	250,727
	Total operating costs and expenses	170,953
	Operating income	79,774
	Interest and investment income	937
	Income from operations before provision for income taxes	80,711
	Provision for income taxes	(22,060		)
	Net income including noncontrolling interests in operating subsidiaries	58,651
	Net loss (income) attributable to noncontrolling interests in operating subsidiaries	164
	Net income attributable to Acacia Research Corporation	$	58,815
		2012
	Pro forma income per common share attributable to Acacia Research Corporation:
	Basic earnings per share	$	1.24
	Diluted earnings per share	$	1.22
	Weighted average number of shares outstanding, basic	47,251,061
	Weighted average number of shares outstanding, diluted	48,060,647
	Pro forma adjustments primarily relate to the amortization of identifiable intangible assets acquired over an estimated economic useful life of ten years, historical operating expenses of ADAPTIX for 2012, and the expensing of acquisition costs incurred by ARG in connection with the Merger.
	The unaudited pro forma combined statements of income for the periods presented herein have been adjusted to give effect to pro forma events that are expected to have a continuing impact on the combined results. As such, the income tax benefit related to the release of valuation allowance reflected in the statement of operations for 2012, as described at Note 9, is not reflected in the accompanying unaudited pro forma combined statements of operations for the periods presented.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY
	Equity Offerings. In February 2012, Acacia raised gross proceeds of $225,000,000 through the sale of 6,122,449 shares of Acacia’s common stock at a price of $36.75 per share in a private placement offering with certain institutional accredited investors. Net proceeds, net of placement agent fees and estimated offering expenses, totaled approximately $218,961,000. The use of proceeds included the finance of pending and future acquisitions of patents and patent royalties and other patent licensing vehicles and companies with patent assets, and for working capital and general corporate purposes.
	Repurchases of Common Stock. On November 16, 2012, Acacia’s Board of Directors authorized a program for repurchases of shares of Acacia’s outstanding common stock. Under the stock repurchase program, effective November 16, 2012, Acacia was authorized to purchase in the aggregate up to $100,000,000 of its outstanding common stock through the period ended May 15, 2013. On April 23, 2013, Acacia’s Board of Directors approved an extension of the stock repurchase program from May 15, 2013 until August 15, 2013. The November 16, 2012 program expired on August 15, 2013.
	On November 15, 2013, Acacia’s Board of Directors authorized a program for repurchases of shares of Acacia’s outstanding common stock. Under the stock repurchase program, effective November 15, 2013, Acacia was authorized to purchase in the aggregate up to $70,000,000 of its of its outstanding common stock through the period ending May 14, 2014.
	Repurchases were made from time to time by Acacia in the open market or in block purchases in compliance with applicable Securities and Exchange Commission rules. Repurchases to date were made using existing cash resources and occurred in the open market. The authorization to repurchase shares presented an opportunity to reduce the outstanding share count and enhance stockholder value. The following is the monthly stock repurchases for the periods presented, all of which were purchased as part of publicly announced plans or programs:
		Total Number of Shares Purchased	Average Price paid per Share		Approximate Dollar Value of		Plan Expiration
					Shares that May Yet be
					Purchased under the Program
	November 16, 2012 - November 30, 2012	256,262	$	21.58	$	—	15-Aug-13
	December 1, 2012 - December 31, 2012	873,146	$	24.26	$	—	15-Aug-13
	Totals for 2012	1,129,408	$	23.65
	December 4, 2013 - December 11, 2013	600,000	$	13.18	$	—	14-May-14
	Totals for 2013	600,000
	Cash Dividends. On April 23, 2013, Acacia announced that its Board of Directors approved the adoption of a cash dividend policy that calls for the payment of an expected total annual cash dividend of $0.50 per common share, payable in the amount of $0.125 per share per quarter. Under the policy, the Company paid four quarterly cash dividends totaling $25,039,000 in 2014 and three quarterly cash dividends totaling $18,633,000 in 2013. While the Company paid dividends to holders of its common stock on a quarterly basis during fiscal years 2014 and 2013, the declaration and payment of future dividends will depend on many factors, including, but not limited to, earnings and financial condition, and any future dividends will be made solely at the discretion of the Board of Directors.
	On February 19, 2015, Acacia announced that its Board of Directors approved a quarterly cash dividend payable in the amount of $0.125 per share. The quarterly cash dividend will be paid on March 30, 2015 to stockholders of record at close of business on March 2, 2015.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES
	Acacia’s provision for income taxes consists of the following for the years ended December 31, (in thousands):
		2014				2013				2012
	Current:
	Federal	$	—			$	—			$	—
	State taxes	289				113				281
	Foreign taxes	5,359				4,405				11,890
	Total current	5,648				4,518				12,171
	Deferred:
	Federal	(1,867		)		(26,151		)		10,085
	State taxes	131				(325		)		(196		)
	Total deferred	(1,736		)		(26,476		)		9,889
	Provision for (benefit from) income taxes	$	3,912			$	(21,958	)		$	22,060
	The tax effects of temporary differences and carryforwards that give rise to significant portions of deferred tax assets and liabilities consist of the following at December 31, 2014 and 2013 (in thousands):
		2014				2013
	Deferred tax assets:
	Net operating loss and capital loss carryforwards and credits	$	59,427			$	34,679
	Stock compensation	1,800				3,052
	Basis of investments in affiliates	1,437				867
	Accrued liabilities and other	409				387
	Unrealized loss on short-term investments	92				337
	State taxes	26				18
	Total deferred tax assets	63,191				39,340
	Valuation allowance	(35,927		)		(7,585		)
	Total deferred tax assets, net of valuation allowance	27,264				31,755
	Deferred tax liabilities:
	Fixed assets and intangibles	(27,157		)		(33,378		)
	Other	(107		)		(112		)
	Total deferred tax liabilities	(27,264		)		(33,490		)
	Net deferred tax assets (liabilities)	$	—			$	(1,735	)
	A reconciliation of the federal statutory income tax rate and the effective income tax rate is as follows:
		2014			2013			2012
	Statutory federal tax rate - (benefit) expense	(35	)%		(35	)%		35	%
	State income and foreign taxes, net of federal tax effect	9	%		5	%		15	%
	Foreign tax credit	(8	)%		(6	)%		(15	)%
	Noncontrolling interests in operating subsidiaries	—	%		1	%		—	%
	Nondeductible permanent items	1	%		2	%		5	%
	Expired net operating loss carryforwards	—	%		2	%		—	%
	Valuation allowance	39	%		4	%		(13	)%
		6	%		(27	)%		27	%
	At December 31, 2013, the Company recorded valuation allowances for certain tax attribute carryforwards and other deferred tax assets due to uncertainty regarding future realizability, as follows:
		2013
	Capital loss carryforwards	$	1,562
	Net operating loss carryforwards	1,281
	Foreign tax credits	4,405
	Unrealized losses on short-term investments and other deferred tax assets	337
	Total valuation allowance	$	7,585
	At December 31, 2014, the Company recorded a full valuation allowance against its net deferred tax assets due to uncertainty regarding future realizability pursuant to guidance set forth in ASC 740, “Income Taxes.” In future periods, if the Company determines it will more likely than not be able to realize certain of these amounts, the applicable portion of the benefit from the release of the valuation allowance will generally be recognized in the statement of operations in the period the determination is made.
	Capital loss carryforwards and certain net operating loss carryforwards included in the valuation allowances for the periods presented expire in varying amounts from 2015 through 2034. Foreign tax credits included in the valuation allowance were generated during the years ended December 31, 2013 and 2014, and expire in 2023 and 2024, respectively.
	As of December 31, 2011, Acacia maintained a full valuation allowance against its net deferred tax assets. The net deferred tax liability resulting from the acquisition of ADAPTIX in January 2012 created an additional source of income to utilize against the majority of Acacia’s existing consolidated net deferred tax assets. In addition, Acacia estimated that certain other deferred tax assets, primarily related to foreign tax credits and other state related deferred tax assets, were more likely than not realizable in future periods. Accordingly, the valuation allowance on the majority of the Company’s net deferred tax assets was released, resulting in a financial statement income tax benefit of $10,651,000 for the year ended December 31, 2012.
	At December 31, 2014, Acacia had U.S. federal and state income tax net operating loss carryforwards (“NOLs”) totaling approximately $118,715,000 and $129,632,000, expiring between 2025 and 2034, and 2015 and 2034, respectively, for which $0 and $441,000 of federal and state net operating losses are included as a deferred tax asset related to the tax benefits of stock option deductions and which will be credited to additional paid-in capital when realized as a reduction of taxes payable on Acacia’s tax return. In addition, $1,928,000 and $37,771,000 of federal and state net operating losses are not included as a deferred tax asset and will be credited to additional paid-in capital when realized as a reduction of taxes payable on Acacia’s tax return as they relate to unrecognized excess tax benefits (see additional information regarding the ordering of windfall tax benefits and use of the “with-and-without” approach below).
	At December 31, 2014, approximately $29,318,000 of the U.S. federal NOLs, acquired in connection with the acquisition of ADAPTIX, are subject to an annual utilization limitation of approximately $14,100,000, pursuant to the “change in ownership” provisions under Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”).
	As of December 31, 2014, Acacia has approximately $29,877,000 of foreign tax credits, expiring between 2015 and 2024, of which $20,313,000 has been utilized for financial statement purposes. Future realization of the credits as a reduction of taxes payable on Acacia’s tax return will result in an income tax benefit recognizable through additional paid in capital since the entire amount of the credits have been utilized for financial statement purposes under the “with-and-without approach.” In general, foreign taxes withheld may be claimed as a deduction on future U.S. corporate income tax returns, or as a credit against future U.S. income tax liabilities, subject to certain limitations.
	Tax expense for fiscal year 2014 primarily reflects foreign taxes withheld on revenue agreements with licensees in foreign jurisdictions, the benefit, totaling $1,735,000, from the reversal of the net deferred tax liability that existed at the beginning of the year and other state taxes. Excluding the impact of the change in valuation allowance in fiscal years 2014, 2013 and 2012, annual effective tax rates were (33)%, (31%), and 40%, respectively. In 2014, the rate at which the Company recorded the tax benefit associated with the pre-tax loss for the period was reduced from the statutory rate primarily due to the full valuation allowance and certain nondeductible permanent items.  The Company recorded a full valuation allowance on its net deferred tax assets, as discussed above, and therefore, did not recognize the related tax benefit in fiscal year 2014, other than the benefit from the reversal of the deferred tax liability that existed at the beginning of the year. In 2013, the rate at which the Company recorded the tax benefit associated with the pre-tax loss for the period was reduced from the statutory rate primarily due to certain nondeductible permanent items and expired capital loss carryforwards.  The Company recorded a valuation allowance on foreign tax credits generated in fiscal year 2013 totaling $4,605,000, as discussed above, and therefore, did not recognize the related tax benefit for these tax assets in fiscal year 2013.  The Company generated pretax income in 2012, resulting in tax expense for the period, and had significant nondeductible permanent items which increased the effective tax rate as shown above. The fiscal year 2012 effective tax rate was lower than the U.S. federal statutory rate primarily due to $10,651,000 million of tax benefits recognized resulting from the release of valuation allowance on the majority of the net deferred tax assets in the first quarter of 2012, as discussed above.
	The Company has elected to utilize the “with-and-without approach” regarding ordering of windfall tax benefits to determine whether the windfall tax benefit has reduced taxes payable. Under this approach, the windfall tax benefits would be recognized in additional paid in capital only if an incremental tax benefit is realized after considering all other tax benefits presently available to the Company. The deductions related to the exercise and vesting of equity-based incentive awards during the periods presented are, in general, available to offset taxable income on Acacia’s consolidated tax returns. Accordingly, the excess tax benefit related to the exercise and vesting of equity-based incentive awards for the periods presented was credited to additional paid-in capital, not taxes payable. The actual tax benefit realized for excess tax deductions resulting from the exercise and vesting of equity-based incentive awards (noncash tax expense) totaled $13,210,000 for the year ended December 31, 2012. For the year ended December 31, 2013, the Company incurred approximately $1,398,000 of net short falls from the exercise and vesting of equity-based incentive awards, of which $1,398,000 was recorded against its additional paid-in capital pool with no impact to the income statement. For the year ended December 31, 2014, the Company incurred approximately $2,713,000 of net short falls from the exercise and vesting of equity-based incentive awards, of which $2,713,000 was recorded against its additional paid-in capital, subject to a full valuation allowance, with no impact to the income statement.
	Acacia is subject to taxation in the U.S. and in various state jurisdictions and incurs foreign tax withholdings on revenue agreements with licensees in certain foreign jurisdictions. With no material exceptions, Acacia is no longer subject to U.S. federal or state examinations by tax authorities for years before 1998. The California Franchise Tax Board is auditing the 2011 and 2012 California combined income tax returns. The audit is in process and no findings or adjustments have been proposed.
	At December 31, 2014, the Company had total unrecognized tax benefits of approximately $2,127,000, including a recorded noncurrent liability of $85,000, related to unrecognized tax benefits primarily associated with state taxes. No interest and penalties have been recorded for the unrecognized tax benefits as of December 31, 2014. If recognized, approximately $2,127,000 would impact the Company’s effective tax rate. The Company does not expect that the liability for unrecognized tax benefits will change significantly within the next 12 months. Activity related to the gross unrecognized tax benefits for the periods presented was as follows (in thousands):
	Balance at January 1, 2012	$	85
	Additions based on tax positions related to the current year	—
	Additions for tax positions related to prior years	772
	Additions resulting from the acquisition of ADAPTIX	1,270
	Reductions	—
	Balance at December 31, 2012	$	2,127
	Balance at December 31, 2013	$	2,127
Balance at December 31, 2014	$	2,127
Acacia recognizes interest and penalties with respect to unrecognized tax benefits in income tax expense. Acacia has identified no uncertain tax position for which it is reasonably possible that the total amount of unrecognized tax benefits will significantly increase or decrease within 12 months.

StockBased_Incentive_Plans

Stock-Based Incentive Plans	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Stock-based Incentive Plans	STOCK-BASED INCENTIVE PLANS
	The 2002 Acacia Technologies Stock Incentive Plan (“2002 Plan”), the 2007 Acacia Technologies Stock Incentive Plan (“2007 Plan”) and the 2013 Acacia Research Corporation Stock Incentive Plan (“2013 Plan”) (collectively, the “Plans”) were approved by the stockholders of Acacia in December 2002, May 2007 and May 2013, respectively. All Plans allow grants of stock options, stock awards and performance shares with respect to Acacia common stock to eligible individuals, which generally includes directors, officers, employees and consultants. Except as noted below, the terms and provisions of the Plans are identical in all material respects. The term of the 2002 Plan expired in December 2012.
	Acacia’s compensation committee administers the discretionary option grant and stock issuance programs. The compensation committee determines which eligible individuals are to receive option grants or stock issuances under those programs, the time or times when the grants or issuances are to be made, the number of shares subject to each grant or issuance, the status of any granted option as either an incentive stock option or a non-statutory stock option under the federal tax laws, the vesting schedule to be in effect for the option grant or stock issuance and the maximum term for which any granted option is to remain outstanding. The exercise price of options is generally equal to the fair market value of Acacia’s common stock on the date of grant. Options generally begin to be exercisable six months to one year after grant and generally expire ten years after grant. Stock options generally vest over two to three years and restricted shares generally vest in full after two to three years (generally representing the requisite service period). The Plans terminate no later than the tenth anniversary of the approval of the incentive plans by Acacia’s stockholders.
	The Plans provide for the following separate programs:
	•	Discretionary Option Grant Program. Under the discretionary option grant program, Acacia’s compensation committee may grant (1) non-statutory options to purchase shares of common stock to eligible individuals in the employ or service of Acacia or its subsidiaries (including employees, non-employee board members and consultants) at an exercise price not less than 85% of the fair market value of those shares on the grant date, and (2) incentive stock options to purchase shares of common stock to eligible employees at an exercise price not less than 100% of the fair market value of those shares on the grant date (not less than 110% of fair market value if such employee actually or constructively owns more than 10% of Acacia’s voting stock or the voting stock of any of its subsidiaries).
	•	Stock Issuance Program. Under the stock issuance program, eligible individuals may be issued shares of common stock directly, upon the attainment of performance milestones or the completion of a specified period of service or as a bonus for past services. Under this program, the purchase price for the shares shall not be less than 100% of the fair market value of the shares on the date of issuance, and payment may be in the form of cash or past services rendered. The eligible individuals shall have full stockholder rights with respect to any shares of Common Stock issued to them under the Stock Issuance Program, whether or not their interest in those shares is vested. Accordingly, the eligible individuals shall have the right to vote such shares and to receive any regular cash dividends paid on such shares.
	•	Automatic Option Grant Program (2002 and 2013Plans only). Commencing in fiscal 2008, each non-employee director will receive restricted stock units for the number of shares determined by dividing the annual retainer by the closing price of Acacia’s common stock on the grant date, provided that such individual has served as a non-employee director for at least 6 months. In addition, as of May 2007, each new non-employee director will receive restricted stock units for the number of shares determined by dividing the annual board of directors retainer by the closing price of Acacia’s common stock on the commencement date. Restricted stock units vest in a series of twelve quarterly installments over the three year period following the grant date, subject to immediate acceleration upon a change in control. Acacia will deliver shares corresponding to the vested restricted stock units within thirty (30) days after the first to occur of the following events: (i) the fifth (5th) anniversary of the grant date; or (ii) termination of the non-employee director’s service as a member of the Company’s Board of Directors. The non-employee directors do not have any rights, benefits or entitlements with respect to any shares unless and until the shares have been delivered.
	The number of shares of common stock available for issuance under the 2002 Plan automatically increased on the first trading day of January each calendar year during the term of the Plan by an amount equal to three percent (3%) of the total number of shares of common stock outstanding on the last trading day in December of the immediately preceding calendar year, not to exceed 500,000 shares. The aggregate number of shares of common stock available for issuance under the 2002 Plan could not exceed 20,000,000 shares. At December 31, 2014, there were no shares available for grant under the expired 2002 Plan.
	The initial share reserve under the 2007 Plan was 560,000 shares. The number of shares of common stock available for issuance under the 2007 Plan automatically increased on January 1, 2008 and 2009, by an amount equal to two percent (2%) of the total number of shares of common stock outstanding on the last trading day of December in the prior calendar year. After January 1, 2009, no new additional shares will be added to the 2007 Plan without stockholder approval (except for shares subject to outstanding awards that are forfeited or otherwise returned to the 2007 Plan). At December 31, 2014, there were no shares available for grant under the 2007 Plan.
	The number of shares of Common Stock initially reserved for issuance under the 2013 Plan was 4,750,000 shares. No new additional shares will be added to the 2013 Plan without security holder approval (except for shares subject to outstanding awards that are forfeited or otherwise returned to the 2013 Plan). The stock issuable under the 2013 Plan shall be shares of authorized but unissued or reacquired Common Stock, including shares repurchased by the Company on the open market. At December 31, 2014, there were 3,243,000 shares available for grant under the 2013 Plan.
	Upon the exercise of stock options, the granting of restricted stock, or the delivery of shares pursuant to vested restricted stock units, it is Acacia’s policy to issue new shares of common stock. Acacia’s board of directors may amend or modify the Plans at any time, subject to any required stockholder approval.
	The following table summarizes stock option activity for the Plans for the year ended December 31, 2014:
					Weighted-Average
			Options		Exercise		Remaining	Aggregate
					Price		Contractual Term	Intrinsic Value
	Outstanding at December 31, 2013		195,000		$	6.91
	Exercised		(45,000	)	$	4.6
	Outstanding at December 31, 2014		150,000		$	7.59	1 year	$	1,402,000
	Vested		150,000		$	7.59	1 year	$	1,402,000
	Exercisable at December 31, 2014		150,000		$	7.59	1 year	$	1,402,000
	The aggregate intrinsic value of options exercised during the years ended December 31, 2014, 2013 and 2012 was $518,000, $2,024,000, and $1,796,000, respectively. No options vested during the years ended December 31, 2014, 2013 and 2012.
	The following table summarizes nonvested restricted share activity for the year ended December 31, 2014:
			Nonvested		Weighted
			Restricted Shares		Average Grant Date Fair Value
	Nonvested restricted stock at December 31, 2013		1,237,000		$	28.23
	Granted		887,000		$	14.41
	Vested		(814,000	)	$	26.4
	Canceled		(292,000	)	$	24.55
	Nonvested restricted stock at December 31, 2014		1,018,000		$	18.71
	The weighted-average grant date fair value of nonvested restricted stock granted during the years ended December 31, 2014, 2013 and 2012 was $14.41, $24.31, and $32.17, respectively. The aggregate fair value of restricted stock that vested during the years ended December 31, 2014, 2013 and 2012 was $21,490,000, $22,317,000, $28,865,000, respectively. As of December 31, 2014, the total unrecognized compensation expense related to nonvested restricted stock awards was $15,012,000, which is expected to be recognized over a weighted-average period of approximately 1.7 years.
	The following table summarizes restricted stock unit activity for the year ended December 31, 2014:
			Restricted		Weighted
			Stock Units		Average Grant Date Fair Value
	Nonvested restricted stock units outstanding at December 31, 2013		20,000		$	27.83
	Granted		33,000		$	14.33
	Vested		(20,000	)	$	22.99
	Nonvested restricted stock units outstanding at December 31, 2014		33,000		$	17.1
	Vested restricted stock units outstanding at December 31, 2014		74,000		$	21.14
	The weighted-average grant date fair value of restricted stock units granted during the years ended December 31, 2014 and 2012 was $14.33 and $29.39, respectively.  There were no restricted units granted during the year ended December 31, 2013. The aggregate fair value of restricted stock units that vested during the years ended December 31, 2014, 2013 and 2012 was $460,000, $469,000 and $363,000, respectively. As of December 31, 2014, the total unrecognized compensation expense related to restricted stock unit awards was $475,000, which is expected to be recognized over a weighted-average period of approximately 1.7 years.
	As of December 31, 2014, there are 3,500,000 shares of common stock are reserved for issuance under the Plans.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	Operating Leases
	Acacia leases certain office space under various operating lease agreements expiring at various dates from 2015 through 2020. Minimum annual rental commitments for operating leases of continuing operations having initial or remaining noncancellable lease terms in excess of one year are as follows (in thousands):
	Years ending December 31,
	2015	$	1,564
	2016	1,595
	2017	1,557
	2018	1,612
	2019	1,669
	Thereafter	166
	Total minimum lease payments	$	8,163
	Rent expense for the years ended December 31, 2014, 2013 and 2012 approximated $1,523,000, $1,312,000 and $898,000, respectively. Rental payments are expensed in the statements of operations in the period to which they relate. Scheduled rent increases are amortized on a straight-line basis over the lease term.
	Inventor Royalties and Contingent Legal Expenses
	In connection with the investment in certain patents and patent rights, certain of Acacia’s operating subsidiaries executed related agreements which grant to the former owners of the respective patents or patent rights, the right to receive inventor royalties based on future net revenues (as defined in the respective agreements) generated as a result of licensing and otherwise enforcing the respective patents or patent portfolios.
	Acacia’s operating subsidiaries may retain the services of law firms that specialize in patent licensing and enforcement and patent law in connection with their licensing and enforcement activities. These law firms may be retained on a contingent fee basis whereby such law firms are paid on a scaled percentage of any negotiated fees, settlements or judgments awarded based on how and when the fees, settlements or judgments are obtained.
	The economic terms of the inventor agreements, operating agreements and contingent legal fee arrangements associated with the patent portfolios owned or controlled by Acacia’s operating subsidiaries, if any, including royalty rates, contingent fee rates and other terms, vary across the patent portfolios owned or controlled by such operating subsidiaries. Inventor royalties, payments to noncontrolling interests and contingent legal fees expenses fluctuate period to period, based on the amount of revenues recognized each period, the terms and conditions of revenue agreements executed each period and the mix of specific patent portfolios with varying economic terms and obligations generating revenues each period. Inventor royalties and contingent legal fees expenses will continue to fluctuate and may continue to vary significantly period to period, based primarily on these factors.
	During the years ended December 31, 2012, Acacia entered into significant agreements with unrelated third-parties resolving pending patent matters that resulted in the grant of certain intellectual property rights and recognition of revenues, portions of which were not subject to inventor royalty and contingent legal fee arrangements, as well as the grant of licenses from certain of Acacia’s operating subsidiaries and recognition of revenues that were subject to inventor royalties and contingent legal fee arrangements. Certain revenues recognized subject to inventor royalties and contingent legal fees are based on a determination by the respective operating subsidiaries.
	Patent Enforcement and Other Litigation
	Acacia is subject to claims, counterclaims and legal actions that arise in the ordinary course of business. Management believes that the ultimate liability with respect to these claims and legal actions, if any, will not have a material effect on Acacia’s consolidated financial position, results of operations or cash flows.
	Certain of Acacia’s operating subsidiaries are often required to engage in litigation to enforce their patents and patent rights. In connection with any of Acacia’s operating subsidiaries’ patent enforcement actions, it is possible that a defendant may request and/or a court may rule that an operating subsidiary has violated statutory authority, regulatory authority, federal rules, local court rules, or governing standards relating to the substantive or procedural aspects of such enforcement actions. In such event, a court may issue monetary sanctions against Acacia or its operating subsidiaries or award attorney’s fees and/or expenses to a defendant(s), which could be material, and if required to be paid by Acacia or its operating subsidiaries, could materially harm the Company’s operating results and financial position.
	During fiscal year 2014, a federal court held that a lawsuit initiated in 2010 was exceptional. Additionally, in a separate matter, a federal court held that a lawsuit initiated in 2011 was exceptional. The total amount requested by these two defendants in these two matters was $2,800,000. The respective operating subsidiaries have filed notices of appeal. Operating expenses for the year ended December 31, 2014 included an accrual for these matters totaling $1,548,000.
	Operating expenses for the year ended December 31, 2013 included a one-time, non-recurring charge related to the resolution of a dispute concerning legal fees associated with a prior matter totaling $3,506,000.
	Guarantees and Indemnifications
	Certain of Acacia’s operating subsidiaries have made guarantees and indemnities under which they may be required to make payments to a guaranteed or indemnified party, in relation to certain transactions, including revenue transactions in the ordinary course of business. In connection with certain facility leases, Acacia and certain of its operating subsidiaries have indemnified lessors for certain claims arising from the facilities or the leases. Acacia indemnifies its directors and officers to the maximum extent permitted under the laws of the State of Delaware. However, Acacia has a directors and officers insurance policy that may reduce its exposure in certain circumstances and may enable it to recover a portion of future amounts that may be payable, if any. The duration of the guarantees and indemnities varies and, in many cases is indefinite but subject to statute of limitations. The majority of guarantees and indemnities do not provide any limitations of the maximum potential future payments that Acacia could be obligated to make. To date, Acacia has made no payments related to these guarantees and indemnities. Acacia estimates the fair value of its indemnification obligations to be insignificant based on this history and therefore, have not recorded any liability for these guarantees and indemnities in the accompanying consolidated balance sheets. Additionally, no events or transactions have occurred that would result in a material liability at December 31, 2014.
	Other
	In August 2010, a wholly owned subsidiary of Acacia became the general partner of the Acacia IP Fund, which was formed in August 2010. The Acacia IP Fund is authorized to raise up to $250,000,000. The Acacia IP Fund invests in, licenses and enforces intellectual property consisting primarily of patents, patent rights, and patented technologies. Refer to Note 2 to these notes to consolidated financial statements for information regarding the consolidation of majority-owned subsidiaries and the presentation of related noncontrolling interests. At December 31, 2014 and 2013, the Acacia IP Fund net assets and net loss were primarily comprised of the following (in thousands):
			2014			2013
	Cash and other assets		$	2,823		$	2,927
	Patents, net of accumulated amortization		967			1,373
	Investments - noncurrent		8,281			11,120
	Total assets		$	12,071		$	15,420
	Accrued expenses and contributions		$	1,876		$	2,437
	Total liabilities		1,876			2,437
	Net assets		$	10,195		$	12,983
			2014			2013
	Revenues		$	1,560		$	1,448
	Operating expenses		1,724			6,907
	Gain from operations		(164		)	(5,459		)
	Net loss in equity method investments		(1,807		)	(542		)
	Net loss		$	(1,971	)	$	(6,001	)

Retirement_Savings_Plan_and_Ex

Retirement Savings Plan and Executive Severance Policy	12 Months Ended
	Dec. 31, 2014
RETIREMENT SAVINGS PLAN AND EXECUTIVE SEVERANCE POLICY [Abstract]
Retirement Savings Plan and Executive Severance Policy	RETIREMENT SAVINGS PLAN AND EXECUTIVE SEVERANCE POLICY
	Retirement Savings Plan.  Acacia has an employee savings and retirement plan under section 401(k) of the Code (the “Plan”). The Plan is a defined contribution plan in which eligible employees may elect to have a percentage of their compensation contributed to the Plan, subject to certain guidelines issued by the Internal Revenue Service. Acacia may contribute to the Plan at the discretion of the board of directors. There were no contributions made by Acacia during the periods presented.
	Executive Severance Policy.  Under Acacia’s Amended Executive Severance Policy, full-time employees with the title of Senior Vice President and higher (“SVP and higher”) are entitled to receive certain benefits upon termination of employment. If employment of an SVP and higher employee is terminated for other than cause or other than on account of death or disability, Acacia will (i) promptly pay to the SVP and higher employee a lump sum amount equal to the aggregate of (a) accrued obligations (i.e., annual base salary through the date of termination to the extent not theretofore paid and any compensation previously deferred (together with any accrued interest or earnings thereon) and any accrued vacation pay, and reimbursable expenses, in each case to the extent not theretofore paid) and (b) three (3) months of base salary for each full year that the SVP and higher employee was employed by the Company (the “Severance Period”), up to a maximum of twelve (12) months (eighteen (18) months for executive officers of Acacia Research Corporation) of base salary, and (ii) provide to the SVP and higher employee, Acacia paid COBRA coverage for the medical and dental benefits selected in the year in which the termination occurs, for the duration of the Severance Period.

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2013
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION
	Estimated federal taxes paid totaled $0, $3,000,000 and $0 for the years ended December 31, 2014, 2013 and 2012, respectively. At December 31, 2013, prepaid expenses and other current assets included federal and state income taxes receivable totaling $3,251,000. Cash paid for state income taxes totaled $172,000, $516,000 and $771,000 for the years ended December 31, 2014, 2013 and 2012, respectively. Foreign taxes withheld totaled $5,159,000, $4,605,000 and $11,890,000 for the years ended December 31, 2014, 2013 and 2012.
	Refer to Note 6 to these notes to consolidated financial statements for information regarding noncash investing activity related to the investment in patent portfolios for the periods presented. Cash flows from financing activities for the year ended December 31, 2012 exclude $504,000 of accrued distributions payable to noncontrolling interests.

Quarterly_Financial_Data

Quarterly Financial Data	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Data [Abstract]
Quarterly Financial Data	QUARTERLY FINANCIAL DATA (unaudited)
	The following table sets forth unaudited consolidated statements of operations data for the eight quarters in the period ended December 31, 2014. This information has been derived from Acacia’s unaudited condensed consolidated financial statements that have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, include all adjustments, consisting of normal recurring adjustments, necessary for a fair statement of the information when read in conjunction with the audited consolidated financial statements and related notes thereto. Acacia’s quarterly results have been, and may in the future be, subject to significant fluctuations. As a result, Acacia believes that results of operations for interim periods should not be relied upon as any indication of the results to be expected in any future periods.
		Quarter Ended
		Mar. 31,			Jun. 30,			Sept. 30,			Dec. 31,			Mar. 31,			Jun. 30,			Sept. 30,			Dec. 31,
		2014			2014			2014			2014			2013			2013			2013			2013
		(Unaudited, in thousands, except share and per share information)
	Revenues	$	12,578		$	50,076		$	37,192		$	31,030		$	76,861		$	23,110		$	15,520		$	15,065
	Operating costs and expenses:
	Cost of revenues:
	Inventor royalties	951			10,694			4,667			4,358			18,481			5,610			2,353			3,280
	Contingent legal fees	1,527			7,077			7,663			7,296			15,032			4,024			2,547			3,181
	Litigation and licensing expenses - patents	8,994			10,820			9,592			8,208			9,648			9,918			10,870			8,899
	Amortization of patents	14,472			15,532			13,511			13,727			11,730			12,578			12,615			16,735
	Marketing, general and administrative expenses (including non-cash stock compensation expense)	11,693			13,181			11,636			12,044			13,844			13,184			18,235			13,988
	Research, consulting and other expenses - business development	992			1,003			1,208			637			1,031			726			730			742
	Other	—			—			1,548			—			—			—			3,506			—
	Total operating costs and expenses	38,629			58,307			49,825			46,270			69,766			46,040			50,856			46,825
	Operating income (loss)	(26,051		)	(8,231		)	(12,633		)	(15,240		)	7,095			(22,930		)	(35,336		)	(31,760		)
	Total other income (expense)	109			(196		)	(57		)	(451		)	1,290			400			280			161
	Income (loss) before (provision for) benefit from income taxes	(25,942		)	(8,427		)	(12,690		)	(15,691		)	8,385			(22,530		)	(35,056		)	(31,599		)
	Benefit from (provision for) income taxes	1,372			(4,689		)	(145		)	(450		)	(3,272		)	9,050			19,570			(3,390		)
	Net income (loss) including noncontrolling interests	(24,570		)	(13,116		)	(12,835		)	(16,141		)	5,113			(13,480		)	(15,486		)	(34,989		)
	Net (income) loss attributable to noncontrolling interests in operating subsidiaries	149			167			420			(103		)	—			977			(225		)	1,656
	Net income (loss) attributable to Acacia Research Corporation	$	(24,421	)	$	(12,949	)	$	(12,415	)	$	(16,244	)	$	5,113		$	(12,503	)	$	(15,711	)	$	(33,333	)
	Net income (loss) per common share attributable to Acacia Research Corporation:
	Basic income (loss) per share - As Adjusted(1)	$	(0.51	)	$	(0.27	)	$	(0.26	)	$	(0.34	)	$	0.1		$	(0.26	)	$	(0.33	)	$	(0.69	)
	Diluted income (loss) per share - As Adjusted(1)	$	(0.51	)	$	(0.27	)	$	(0.26	)	$	(0.34	)	$	0.1		$	(0.26	)	$	(0.33	)	$	(0.69	)
	Weighted-average number of shares outstanding, basic - As Adjusted(1)	48,329,375			48,543,334			48,806,334			48,944,914			47,859,774			48,008,998			48,330,149			48,415,684
	Weighted-average number of shares outstanding, diluted - As Adjusted(1)	48,329,375			48,543,334			48,806,334			48,944,914			48,104,242			48,008,998			48,330,149			48,415,684
		Quarter Ended
		Mar. 31,		Jun. 30,	Sept. 30,		Dec. 31,	Mar. 31,			Jun. 30,			Sept. 30,		Dec. 31,
		2014		2014	2014		2014	2013			2013			2013		2013
		(Unaudited, In thousands, except share and per share information)
	Basic income (loss) per share - As Reported(1)	N/A		N/A	N/A		N/A	$	0.11		$	(0.26	)	N/A		N/A
	Diluted income (loss) per share - As Reported(1)	N/A		N/A	N/A		N/A	$	0.11		$	(0.26	)	N/A		N/A
	Weighted-average number of shares outstanding, basic - As Reported(1)	N/A		N/A	N/A		N/A	47,859,774			48,008,998			N/A		N/A
	Weighted-average number of shares outstanding, diluted - As Reported(1)	N/A		N/A	N/A		N/A	48,354,444			48,008,998			N/A		N/A
	_______________________
	(1) - Revision of Prior Period Earnings (Loss) Per Share - Two-Class Method. In connection with the preparation of the Company’s Quarterly Report on Form 10-Q as of and for the three months ended September 30, 2013, the Company determined that its basic and diluted net income (loss) per share calculations should have been prepared using the “two-class method.” Under the two-class method, securities that participate in dividends are considered “participating securities.” The Company’s unvested restricted shares outstanding are considered “participating securities” because they include non-forfeitable rights to dividends.
	Pursuant to guidance set forth in Staff Accounting Bulletin (“SAB”) No. 99, “Materiality,” the Company concluded that the errors were not material to any of its prior period financial statements. Although the errors were immaterial to prior periods, the prior period financial statements presented herein were revised, in accordance with SAB No. 108, “Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements.”

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Fiscal Period	Accounting Principles and Fiscal Year End.  The consolidated financial statements and accompanying notes are prepared on the accrual basis of accounting in accordance with generally accepted accounting principles in the United States of America.
Consolidation, Subsidiaries or Other Investments, Consolidated Entities	Principles of Consolidation.  The accompanying consolidated financial statements include the accounts of Acacia and its wholly and majority-owned and controlled subsidiaries. Material intercompany transactions and balances have been eliminated in consolidation.
Net income (loss) attributable to noncontrolling interest	Noncontrolling interests in Acacia’s majority-owned and controlled operating subsidiaries (“noncontrolling interests”) are separately presented as a component of stockholders’ equity. Consolidated net income or (loss) is adjusted to include the net (income) or loss attributed to noncontrolling interests in the consolidated statements of operations. Refer to the accompanying consolidated statements of stockholders’ equity for total noncontrolling interests.
	In August 2010, a wholly owned subsidiary of Acacia became the general partner of the Acacia Intellectual Property Fund, L.P. (the “Acacia IP Fund”), which was formed in August 2010. The Acacia IP Fund is included in the Company’s consolidated financial statements since 2010, as Acacia’s wholly owned subsidiary, as the general partner, has the ability to control the operations and activities of the Acacia IP Fund. Refer to Note 11 to these consolidated financial statements.
Revenue Recognition	Revenue Recognition.  Revenue is recognized when (i) persuasive evidence of an arrangement exists, (ii) all obligations have been substantially performed pursuant to the terms of the arrangement, (iii) amounts are fixed or determinable, and (iv) the collectibility of amounts is reasonably assured.
	In general, revenue arrangements provide for the payment of contractually determined fees in consideration for the grant of certain intellectual property rights for patented technologies owned or controlled by Acacia’s operating subsidiaries. These rights typically include some combination of the following: (i) the grant of a non-exclusive, retroactive and future license to manufacture and/or sell products covered by patented technologies owned or controlled by Acacia’s operating subsidiaries, (ii) a covenant-not-to-sue, (iii) the release of the licensee from certain claims, and (iv) the dismissal of any pending litigation. The intellectual property rights granted may be perpetual in nature, extending until the expiration of the related patents, or can be granted for a defined, relatively short period of time, with the licensee possessing the right to renew the agreement at the end of each contractual term for an additional minimum upfront payment. Pursuant to the terms of these agreements, Acacia’s operating subsidiaries have no further obligation with respect to the grant of the non-exclusive retroactive and future licenses, covenants-not-to-sue, releases, and other deliverables, including no express or implied obligation on Acacia’s operating subsidiaries’ part to maintain or upgrade the technology, or provide future support or services. Generally, the agreements provide for the grant of the licenses, covenants-not-to-sue, releases, and other significant deliverables upon execution of the agreement, or upon receipt of the minimum upfront payment for term agreement renewals. As such, the earnings process is complete and revenue is recognized upon the execution of the agreement, when collectibility is reasonably assured, or upon receipt of the minimum upfront fee for term agreement renewals, and when all other revenue recognition criteria have been met.
	For the periods presented herein, the majority of the revenue agreements executed by the Company provided for the payment of one-time, paid-up license fees in consideration for the grant of certain intellectual property rights for patented technology rights owned by our operating subsidiaries. These rights were primarily granted on a perpetual basis, extending until the expiration of the underlying patents.
	Certain of the Company’s revenue arrangements provide for future royalties or additional required payments based on future licensee activities. Additional royalties are recognized in revenue upon resolution of the related contingency provided that all revenue recognition criteria, as described above, have been met. Amounts of additional royalties due under these license agreements, if any, cannot be reasonably estimated by management.
	Certain of the Company’s revenue arrangements provide for the calculation of fees based on a licensee’s actual quarterly sales or actual per unit activity, applied to a contractual royalty rate. Licensees that pay fees on a quarterly basis generally report actual quarterly sales or actual per unit activity information and related quarterly fees due within 30 days to 45 days after the end of the quarter in which such sales or activity takes place. The amount of fees due under these revenue arrangements each quarter cannot be reasonably estimated by management. Consequently, Acacia’s operating subsidiaries recognize revenue from these revenue arrangements on a three-month lag basis, in the quarter following the quarter of sales or per unit activity, provided amounts are fixed or determinable and collectibility is reasonably assured. The lag method described above allows for the receipt of licensee royalty reports prior to the recognition of revenue.
	Amounts related to revenue arrangements that do not meet the revenue recognition criteria described above are deferred until the revenue recognition criteria are met.
	Acacia assesses the collectibility of fees receivable based on a number of factors, including past transaction history and credit-worthiness of licensees. If it is determined that collection is not reasonably assured, the fee is recognized when collectibility becomes reasonably assured, assuming all other revenue recognition criteria have been met, which is generally upon receipt of cash.
Cost of Revenues	Cost of Revenues.  Cost of revenues include the costs and expenses incurred in connection with Acacia’s patent licensing and enforcement activities, including inventor royalties paid to original patent owners, contingent legal fees paid to external patent counsel, other patent-related legal expenses paid to external patent counsel, licensing and enforcement related research, consulting and other expenses paid to third-parties and the amortization of patent-related investment costs. These costs are included under the caption “Cost of revenues” in the accompanying consolidated statements of operations.
Inventor Royalties and Contingent Legal Expenses	Inventor Royalties and Contingent Legal Expenses. Inventor royalties are expensed in the consolidated statements of operations in the period that the related revenues are recognized. In certain instances, pursuant to the terms of the underlying inventor agreements, upfront advances paid to patent owners by Acacia’s operating subsidiaries are recoverable from future net revenues. Patent costs that are recoverable from future net revenues are amortized over the estimated economic useful life of the related patents, or as the prepaid royalties are earned by the inventor, as appropriate, and the related expense is included in amortization expense in the consolidated statements of operations. Any unamortized patent portfolio investment costs recovered from net revenues are expensed in the period recovered, and included in amortization expense in the consolidated statements of operations. Refer to Note 11 for additional information.
	Contingent legal fees are expensed in the consolidated statements of operations in the period that the related revenues are recognized. In instances where there are no recoveries from potential infringers, no contingent legal fees are paid; however, Acacia’s operating subsidiaries may be liable for certain out of pocket legal costs incurred pursuant to the underlying legal services agreement.
Fair Value Measurements	Fair Value Measurements. U.S. generally accepted accounting principles define fair value as the price that would be received for an asset or the exit price that would be paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants on the measurement date, and also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs, where available. The three-level hierarchy of valuation techniques established to measure fair value is defined as follows:
		●	Level 1 -	Observable Inputs:  Quoted prices in active markets for identical investments;
		●	Level 2 -	Pricing Models with Significant Observable Inputs:  Other significant observable inputs, including quoted prices for similar investments, interest rates, credit risk, etc.; and
		●	Level 3 -	Unobservable Inputs:  Significant unobservable inputs, including the entity’s own assumptions in determining the fair value of investments.
	Whenever possible, the Company is required to use observable market inputs (Level 1 - quoted market prices) when measuring fair value. Acacia has not elected the fair value option for recording non-financial assets and liabilities, and therefore no fair value measurements are performed on a recurring basis.
Cash and Cash Equivalents	Cash and Cash Equivalents.  Acacia considers all highly liquid, short-term investments with original maturities of three months or less when purchased to be cash equivalents. For the periods presented, Acacia’s cash equivalents are comprised of investments in AAA rated money market funds that invest in first-tier only securities, which primarily includes: domestic commercial paper, securities issued or guaranteed by the U.S. government or its agencies, U.S. bank obligations, and fully collateralized repurchase agreements. Acacia’s cash equivalents are measured at fair value using quoted prices that represent Level 1 inputs.
Marketable Securities	Investments in Marketable Securities.  Investments in securities with original maturities of greater than three months and less than one year and other investments representing amounts that are available for current operations are classified as short-term investments, unless there are indications that such investments may not be readily sold in the short term. The fair values of these investments approximate their carrying values. At December 31, 2014 and 2013, all of Acacia’s investments were classified as available-for-sale, which are reported at fair value on a recurring basis using significant observable inputs (Level 1), with related unrealized gains and losses in the value of such securities recorded as a separate component of other comprehensive income (loss) in stockholders’ equity until realized. Realized and unrealized gains and losses are recorded based on the specific identification method. Interest on all securities is included in interest and other investment income (loss).
	Impairment of Marketable Securities. Acacia evaluates its investments in marketable securities for potential impairment, employing a systematic methodology on a quarterly basis that considers available quantitative and qualitative evidence. If the cost or carrying value of an investment exceeds its estimated fair value, the Company evaluates, among other factors, general market conditions, credit quality of instrument issuers, the duration and extent to which the fair value is less than cost, and the Company’s intent and ability to hold, or plans or ability to sell. Fair value is estimated based on publicly available market information or other estimates determined by management. Investments are considered to be impaired when a decline in fair value is estimated to be other-than-temporary. Acacia reviews impairments associated with its investments in marketable securities and determines the classification of any impairment as temporary or other-than-temporary. An impairment is deemed other-than-temporary unless (a) Acacia has the ability and intent to hold an investment for a period of time sufficient for recovery of its carrying amount and (b) positive evidence indicating that the investment’s carrying amount is recoverable within a reasonable period of time outweighs any evidence to the contrary. All available evidence, both positive and negative, is considered to determine whether, based on the weight of such evidence, the carrying amount of the investment is recoverable within a reasonable period of time. For investments classified as available-for-sale, unrealized losses that are other-than-temporary are recognized in the consolidated statements of operations.
Concentrations of Credit Risk	Concentration of Credit Risks.  Financial instruments that potentially subject Acacia to concentrations of credit risk are cash equivalents, investments and accounts receivable. Acacia places its cash equivalents and investments primarily in highly rated money market funds and investment grade marketable securities. Cash equivalents are also invested in deposits with certain financial institutions and may, at times, exceed federally insured limits. Acacia has not experienced any significant losses on its deposits of cash and cash equivalents.
	Two licensees individually accounted for 22% and 22%, respectively, of revenues recognized during the year ended December 31, 2014. Two licensees individually accounted for 38% and 16%, respectively, of revenues recognized during the year ended December 31, 2013. Four licensees individually accounted for 21%, 14%, 10% and 10%, respectively, of revenues recognized during the year ended December 31, 2012. Three licensees individually represented approximately 30%, 17% and 15%, respectively, of accounts receivable at December 31, 2014. Two licensees individually represented approximately 60% and 22% of accounts receivable at December 31, 2013. For 2014, 2013 and 2012, 43%, 24% and 43%, respectively, of revenues were attributable to licensees domiciled in foreign jurisdictions, based on the jurisdiction of the entity obligated to satisfy payment obligations pursuant to the applicable revenue arrangement. The Company does not have any material foreign operations.
	Acacia performs credit evaluations of its licensees with significant receivable balances, if any, and has not experienced any significant credit losses. Accounts receivable are recorded at the executed contract amount and generally do not bear interest. Collateral is not required. An allowance for doubtful accounts may be established to reflect the Company’s best estimate of probable losses inherent in the accounts receivable balance, and is reflected as a contra-asset account on the balance sheet and a charge to operating expenses in the statement of operations for the applicable period. The allowance is determined based on known troubled accounts, historical experience, and other currently available evidence. There was no allowance for doubtful accounts established for the periods presented.
Furniture and Equipment	Furniture and Equipment.  Furniture and equipment are recorded at cost. Major additions and improvements that materially extend useful lives of furniture and equipment are capitalized. Maintenance and repairs are charged against the results of operations as incurred. When these assets are sold or otherwise disposed of, the asset and related depreciation are relieved, and any gain or loss is included in the consolidated statements of operations for the period of sale or disposal. Depreciation and amortization is computed on a straight-line basis over the following estimated useful lives of the assets:
	Furniture and fixtures	3 to 5 years
	Computer hardware and software	3 to 5 years
	Leasehold improvements	2 to 5 years (Lesser of lease term or useful life of improvement)
	Rental payments on operating leases are charged to expense in the consolidated statements of operations on a straight-line basis over the lease term.
Patents	Patents.  Patents include the cost of patents or patent rights (hereinafter, collectively “patents”) acquired from third-parties or obtained in connection with business combinations. Patent costs are amortized utilizing the straight-line method over their remaining economic useful lives, ranging from one to ten years. Certain patent application and prosecution costs incurred to secure additional patent claims, that based on management’s estimates are deemed to be recoverable, are capitalized and amortized over the remaining estimated economic useful life of the related patent portfolio.
Goodwill	Goodwill. Goodwill is tested for impairment at the reporting unit level (operating segment or one level below an operating segment) on an annual basis (December 31) and between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value. Acacia considers its market capitalization and the carrying value of its assets and liabilities, including goodwill, when performing its goodwill impairment test. When conducting its annual goodwill impairment assessment, the Company initially performs a qualitative evaluation of whether it is more likely than not that goodwill is impaired. If it is determined by a qualitative evaluation that it is more likely than not that goodwill is impaired, the Company then applies a two-step impairment test. The two-step impairment test first compares the fair value of the Company’s reporting unit to its carrying or book value. If the fair value of the reporting unit exceeds its carrying value, goodwill is not impaired and the Company is not required to perform further testing. If the carrying value of the reporting unit exceeds its fair value, the Company determines the implied fair value of the reporting unit’s goodwill and if the carrying value of the reporting unit’s goodwill exceeds its implied fair value, then an impairment loss equal to the difference is recorded in the consolidated statement of operations.
Impairment of Long-Lived Assets	Impairment of Long-lived Assets. Acacia reviews long-lived assets and intangible assets for potential impairment annually (quarterly for patents) and when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. In the event the expected undiscounted future cash flows resulting from the use of the asset is less than the carrying amount of the asset, an impairment loss is recorded equal to the excess of the asset’s carrying value over its fair value. If an asset is determined to be impaired, the loss is measured based on quoted market prices in active markets, if available. If quoted market prices are not available, the estimate of fair value is based on various valuation techniques, including a discounted value of estimated future cash flows.
	Fair value is generally estimated using the “Income Approach,” focusing on the estimated future net income-producing capability of the patent portfolios over the estimated remaining economic useful life. Estimates of future after-tax cash flows are converted to present value through “discounting,” including an estimated rate of return that accounts for both the time value of money and investment risk factors. Estimated cash inflows are typically based on estimates of reasonable royalty rates for the applicable technology, applied to estimated market share data. Estimated cash outflows are based on existing contractual obligations, such as contingent legal fee and inventor royalty obligations, applied to estimated license fee revenues, in addition to other estimates of out-of-pocket expenses associated with a specific patent portfolio’s licensing and enforcement program. The analysis also contemplates consideration of current information about the patent portfolio including, status and stage of litigation, periodic results of the litigation process, strength of the patent portfolio, technology coverage and other pertinent information that could impact future net cash flows.
Fair Value of Financial Instruments	Fair Value of Financial Instruments.  The carrying value of cash and cash equivalents, investments, accounts receivables, accounts payable and accrued expenses approximates their fair values due to their short-term maturities.
Contingent liabilities [Policy Text Block]	Contingent Liabilities. The Company, from time to time, is involved in certain legal proceedings. Based upon consultation with outside counsel handling its defense in these matters and the Company’s analysis of potential outcomes, if the Company determines that a loss arising from such matters is probable and can be reasonably estimated, an estimate of the contingent liability is recorded in its consolidated financial statements. If only a range of estimated loss can be determined, an amount within the range that, based on estimates, assumptions and judgments, reflects the most likely outcome, is recorded as a contingent liability in the consolidated financial statements. In situations where none of the estimates within the estimated range is a better estimate of probable loss than any other amount, the Company records the low end of the range. Any such accrual would be charged to expense in the appropriate period. Litigation expenses for these types of contingencies are recognized in the period in which the litigation services were provided.
Stock-based Compensation	Stock-Based Compensation. The compensation cost for all stock-based awards is measured at the grant date, based on the fair value of the award, and is recognized as an expense on a straight-line basis over the employee’s requisite service period (generally the vesting period of the equity award) which is generally two to four years. The fair value of restricted stock and restricted stock unit awards is determined by the product of the number of shares or units granted and the grant date market price of the underlying common stock. The fair value of each option award is estimated on the date of grant using a Black-Scholes option valuation model. Stock-based compensation expense is recorded only for those awards expected to vest using an estimated forfeiture rate. Refer to Note 10 to these notes to consolidated financial statements for information on stock-based awards granted for the periods presented.
Income Taxes	Income Taxes.  Income taxes are accounted for using an asset and liability approach that requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in Acacia’s consolidated financial statements or consolidated income tax returns. A valuation allowance is established to reduce deferred tax assets if all, or some portion, of such assets will more than likely not be realized, or if it is determined that there is uncertainty regarding future realizability of such assets.
	Under U.S. generally accepted accounting principles, a tax position is a position in a previously filed tax return or a position expected to be taken in a future tax filing that is reflected in measuring current or deferred income tax assets and liabilities. Tax positions are recognized only when it is more likely than not (likelihood of greater than 50%), based on technical merits, that the position will be sustained upon examination. Tax positions that meet the more likely than not threshold are measured using a probability weighted approach as the largest amount of tax benefit that is greater than 50% likely of being realized upon settlement.
	If a deduction reported on a tax return for an equity-based incentive award exceeds the cumulative compensation cost for those instruments recognized for financial reporting purposes, any resulting realized tax benefit that exceeds the previously calculated deferred tax asset for those instruments is considered an excess tax benefit, and is recognized as additional paid-in capital. If the tax deduction is less than the cumulative book compensation cost, the tax effect of the resulting difference is charged first to APIC, to the extent of the available pool of windfall tax benefits, with any remainder recognized in income tax expense.
Segment Reporting	Segment Reporting.  Acacia uses the management approach, which designates the internal organization that is used by management for making operating decisions and assessing performance as the basis of Acacia’s reportable segments. Acacia’s patent licensing and enforcement business constitutes its single reportable segment.
Use of Estimates	Use of Estimates.  The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. Acacia believes that, of the significant accounting policies described herein, the accounting policies associated with revenue recognition, stock-based compensation expense, impairment of marketable securities and intangible assets, the determination of the economic useful life of amortizable intangible assets, income taxes and valuation allowances against net deferred tax assets and the application of the acquisition method of accounting for business combinations, require its most difficult, subjective or complex judgments.
Earnings Per Share	Income (Loss) Per Share.  The Company computes net income (loss) attributable to common stockholders using the two-class method required for capital structures that include participating securities. Under the two-class method, securities that participate in non-forfeitable dividends, such as the Company’s outstanding unvested restricted stock, are considered “participating securities.”
	In applying the two-class method, (i) basic net income (loss) per share is computed by dividing net income (loss) (less any dividends paid on participating securities) by the weighted average number of shares of common stock and participating securities outstanding for the period and (ii) diluted earnings per share may include the additional effect of other securities, if dilutive, in which case the dilutive effect of such securities is calculated by applying the two-class method and the treasury stock method to the assumed exercise or vesting of potentially dilutive common shares. The method yielding the more dilutive result is ultimately reported for the applicable period. Potentially dilutive common stock equivalents primarily consist of employee stock options, and restricted stock units for calculations utilizing the two-class method, and also include unvested restricted stock, when utilizing the treasury method.
	The following table presents the weighted-average number of common shares outstanding used in the calculation of basic and diluted income per share:
			2014			2013			2012
	Numerator (in thousands):
	Basic
	Net income (loss)		$	(66,029	)	$	(56,434	)	$	59,453
	Undistributed earnings allocated to participating securities		—			—			(1,889		)
	Total dividends paid		(25,039		)	(18,633		)	—
	Dividends attributable to common stockholders		24,313			18,122			—
	Net income (loss) attributable to common stockholders – basic		$	(66,755	)	$	(56,945	)	$	57,564
	Diluted
	Net income (loss)		$	(66,029	)	$	(56,434	)	$	59,453
	Undistributed earnings allocated to participating securities		—			—			(1,876		)
	Total dividends paid		(25,039		)	(18,633		)	—
	Dividends attributable to common stockholders		24,313			18,122			—
	Net income (loss) attributable to common stockholders – diluted		$	(66,755	)	$	(56,945	)	$	57,577
	Denominator:
	Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – basic		48,658,088			48,155,832			47,251,061
	Effect of potentially dilutive securities:
	Common stock options and restricted stock units		—			—			333,059
	Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – diluted		48,658,088			48,155,832			47,584,120
	Basic net income (loss) per common share		$	(1.37	)	$	(1.18	)	$	1.22
	Diluted net income (loss) per common share		$	(1.37	)	$	(1.18	)	$	1.21
	Anti-dilutive equity-based incentive awards excluded from the computation of diluted income (loss) per share		27,760			27,760			30,812
	Revision of Prior Period Earnings (Loss) Per Share - Two-Class Method. In connection with the preparation of the Company’s Quarterly Report on Form 10-Q as of and for the three and nine months ended September 30, 2013, the Company determined that its basic and diluted net income (loss) per share calculations should have been prepared using the “two-class method.” Pursuant to guidance set forth in Staff Accounting Bulletin (“SAB”) No. 99, “Materiality,” the Company concluded that the errors were not material to any of its prior period financial statements. Although the errors were immaterial to prior periods, the prior period financial statements presented herein were revised, in accordance with SAB No. 108, “Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements.” The impact of the revision for the comparable prior period earnings (loss) per share calculations using the two-class method were as follows:
			2012
	Numerator:
	Net income attributable to common stockholders – basic and diluted - As Reported		$	59,453
	Net income attributable to common stockholders – basic - As Adjusted		$	57,564
	Net income attributable to common stockholders – diluted - As Adjusted		$	57,577
	Denominator:
	Weighted-average shares used in computing net income per share attributable to common stockholders – basic - As Reported		47,251,061
	Weighted-average shares used in computing net income per share attributable to common stockholders – basic - As Adjusted		47,251,061
	Weighted-average shares used in computing net income per share attributable to common stockholders – diluted - As Reported		48,060,647
	Weighted-average shares used in computing net income per share attributable to common stockholders – diluted - As Adjusted		47,584,120
	Basic net income per common share - As Reported		$	1.26
	Basic net income per common share - As Adjusted		$	1.22
	Diluted net income per common share - As Reported		$	1.24
	Diluted net income per common share - As Adjusted		$	1.21
Treasury Stock [Policy Text Block]	Treasury Stock. Repurchases of the Company’s outstanding common stock are accounted for using the cost method. The applicable par value is deducted from the appropriate capital stock account on the formal or constructive retirement of treasury stock. Any excess of the cost of treasury stock over its par value is charged to additional paid-in capital, and reflected as Treasury Stock on the consolidated balance sheets.
Recently Adopted Accounting Policies	Recent Accounting Pronouncements - Not Yet Adopted. In June 2014, the Financial Accounting Standards Board (the “FASB”) issued a new accounting standard which requires that a performance target that affects vesting and could be achieved after the requisite service period shall be treated as a performance condition. Adoption of this standard is required for annual periods beginning after December 15, 2015. Early adoption is permitted. The Company is currently evaluating the impact the pronouncement will have on its consolidated financial statements and related disclosures.
	In May 2014, the FASB issued a new accounting standards update addressing revenue from contracts with customers, which clarifies existing accounting literature relating to how and when a company recognizes revenue.  Under the standard, a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods and services.  The amendments for this standard update are effective for interim and annual reporting periods beginning after December 15, 2016, and are to be applied
	retrospectively or the cumulative effect as of the date of adoption, with early application not permitted.  The Company is currently evaluating the impact and method of adoption the pronouncement will have on its consolidated financial statements and related disclosures.
	In August 2014, the FASB issued a new accounting standard which requires management to assess an entity’s ability to continue as a going concern every reporting period including interim periods, and to provide related footnote disclosure in certain circumstances. Adoption of this standard is required for annual periods beginning after December 15, 2016 and are to be applied retrospectively or the cumulative effect as of the date of adoption. Early adoption is permitted. The Company is currently evaluating the impact the pronouncement will have on its consolidated financial statements and related disclosures.
Recently adopted accounting policies [Policy Text Block]	Recently Adopted Accounting Pronouncements - Adopted Effective January 1, 2014. In July 2013, the FASB issued a new accounting standard addressing when unrecognized tax benefits should be presented as reductions to deferred tax assets for net operating loss carryforwards in the financial statements. This standard was adopted effective January 1, 2014. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and related disclosures.
	In March 2013, the FASB issued a new accounting standard addressing the accounting for the cumulative translation adjustment when a parent either sells a part or all of its investment in a foreign entity or no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity. This standard was adopted effective January 1, 2014. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and related disclosures.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Property and Equipment, Useful Lives	Depreciation and amortization is computed on a straight-line basis over the following estimated useful lives of the assets:
	Furniture and fixtures	3 to 5 years
	Computer hardware and software	3 to 5 years
	Leasehold improvements	2 to 5 years (Lesser of lease term or useful life of improvement)
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the weighted-average number of common shares outstanding used in the calculation of basic and diluted income per share:
			2014			2013			2012
	Numerator (in thousands):
	Basic
	Net income (loss)		$	(66,029	)	$	(56,434	)	$	59,453
	Undistributed earnings allocated to participating securities		—			—			(1,889		)
	Total dividends paid		(25,039		)	(18,633		)	—
	Dividends attributable to common stockholders		24,313			18,122			—
	Net income (loss) attributable to common stockholders – basic		$	(66,755	)	$	(56,945	)	$	57,564
	Diluted
	Net income (loss)		$	(66,029	)	$	(56,434	)	$	59,453
	Undistributed earnings allocated to participating securities		—			—			(1,876		)
	Total dividends paid		(25,039		)	(18,633		)	—
	Dividends attributable to common stockholders		24,313			18,122			—
	Net income (loss) attributable to common stockholders – diluted		$	(66,755	)	$	(56,945	)	$	57,577
	Denominator:
	Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – basic		48,658,088			48,155,832			47,251,061
	Effect of potentially dilutive securities:
	Common stock options and restricted stock units		—			—			333,059
	Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – diluted		48,658,088			48,155,832			47,584,120
	Basic net income (loss) per common share		$	(1.37	)	$	(1.18	)	$	1.22
	Diluted net income (loss) per common share		$	(1.37	)	$	(1.18	)	$	1.21
	Anti-dilutive equity-based incentive awards excluded from the computation of diluted income (loss) per share		27,760			27,760			30,812
Impact of the Revision to the Comparable Prior Period Earnings (Loss) Per Share Calculations Using the Two-Class Method [Table Text Block]	The impact of the revision for the comparable prior period earnings (loss) per share calculations using the two-class method were as follows:
			2012
	Numerator:
	Net income attributable to common stockholders – basic and diluted - As Reported		$	59,453
	Net income attributable to common stockholders – basic - As Adjusted		$	57,564
	Net income attributable to common stockholders – diluted - As Adjusted		$	57,577
	Denominator:
	Weighted-average shares used in computing net income per share attributable to common stockholders – basic - As Reported		47,251,061
	Weighted-average shares used in computing net income per share attributable to common stockholders – basic - As Adjusted		47,251,061
	Weighted-average shares used in computing net income per share attributable to common stockholders – diluted - As Reported		48,060,647
	Weighted-average shares used in computing net income per share attributable to common stockholders – diluted - As Adjusted		47,584,120
	Basic net income per common share - As Reported		$	1.26
	Basic net income per common share - As Adjusted		$	1.22
	Diluted net income per common share - As Reported		$	1.24
	Diluted net income per common share - As Adjusted		$	1.21

Shortterm_Investments_Tables

Short-term Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Short-term Investments [Abstract]
Short-term Investments	Short-term marketable securities for the periods presented were comprised of the following (in thousands):
		December 31, 2014
	Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	U.S. government fixed income securities	$	58,819	$	2	$	(263	)	$	58,558
	Total short-term investments	$	58,819	$	2	$	(263	)	$	58,558
		December 31, 2013
	Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	U.S. government fixed income securities	$	130,971	$	21	$	(975	)	$	130,017
	Total short-term investments	$	130,971	$	21	$	(975	)	$	130,017

Furniture_and_Equipment_Tables

Furniture and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and Equipment	and equipment consists of the following at December 31, 2014 and 2013 (in thousands):
		2014			2013
	Furniture and fixtures	$	761		$	783
	Computer hardware and software	650			687
	Leasehold improvements	144			306
		1,555			1,776
	Less:  accumulated depreciation and amortization	(1,055		)	(1,010		)
		$	500		$	766

Accounts_Payable_and_Accrued_E1

Accounts Payable and Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accounts Payable and Accrued Expenses / Costs	Accounts payable and accrued expenses consist of the following at December 31, 2014 and 2013 (in thousands):
		2014		2013
	Accounts payable	$	121	$	128
	Payroll and other employee benefits	1,481		1,039
	Accrued vacation	806		813
	Accrued legal expenses - patent	8,410		5,900
	Accrued attorney's fees	1,548		—
	Accrued consulting and other professional fees	1,530		2,948
	Accrued distribution to noncontrolling interests	—		504
	Other accrued liabilities	964		223
		$	14,860	$	11,555

Patents_Tables

Patents (Tables)	12 Months Ended
	Dec. 31, 2014
Patents [Abstract]
Patents	The gross carrying amounts and accumulated amortization related to investments in intangible assets as of December 31, 2014 and 2013 are as follows (in thousands):
		2014			2013
	Gross carrying amount - patents	$	453,201		$	400,755
	Accumulated amortization - patents	(166,565		)	(112,323		)
	Patents, net	$	286,636		$	288,432
Patent costs and accumulated amortization related to patent sales and disposals [Table Text Block]	For the years ended December 31, 2014, 2013 and 2012, capitalized patent costs and accumulated amortization, and sales proceeds and other costs, related to patent-related sales and disposals are as follows (in thousands):
		2014			2013			2012
	Capitalized patent costs	$	3,000		$	3,500		$	5,500
	Accumulated amortization	298			1,753			2,466
	Sales proceeds	3,500			1,000			2,792

Acquisition_Tables

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Schedule of Purchase Price Allocation	The total consideration paid by ARG in connection with the Merger was approximately $160,000,000, in cash. Based on the total purchase consideration and the estimate of the assets acquired and the liabilities assumed by ARG as of the Acquisition Date, the purchase price allocation was as follows ($ amounts in thousands):
						Amortization Period		Annual Amortization
	Assets Acquired and Liabilities Assumed:
	Fair value of net tangible assets acquired		$	10,000
	Intangible assets acquired - patents		150,000			10 years		$	15,000
	Goodwill		30,149
	Net deferred income tax liability		(30,149		)
	Total		$	160,000
Deferred Tax Liability, Acquisition	The estimated net deferred tax liability was determined as follows ($ amounts in thousands):
			Book Basis			Tax Basis				Difference
	Intangible assets acquired - patents		$	150,000		$	—			$	(150,000	)
	Estimated acquired deferred tax assets (including net operating loss carryforwards) - ADAPTIX		—			63,860				63,860
	Net deferred tax liability - pretax									(86,140		)
	Estimated tax rate									35		%
	Estimated net deferred tax liability									$	(30,149	)
Business Acquisition, Pro Forma Information	The unaudited pro forma combined results are presented in thousands, except share and per share information.
		2012
	Revenues	$	250,727
	Total operating costs and expenses	170,953
	Operating income	79,774
	Interest and investment income	937
	Income from operations before provision for income taxes	80,711
	Provision for income taxes	(22,060		)
	Net income including noncontrolling interests in operating subsidiaries	58,651
	Net loss (income) attributable to noncontrolling interests in operating subsidiaries	164
	Net income attributable to Acacia Research Corporation	$	58,815
		2012
	Pro forma income per common share attributable to Acacia Research Corporation:
	Basic earnings per share	$	1.24
	Diluted earnings per share	$	1.22
	Weighted average number of shares outstanding, basic	47,251,061
	Weighted average number of shares outstanding, diluted	48,060,647

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Schedule of Treasury Stock by Class	ollowing is the monthly stock repurchases for the periods presented, all of which were purchased as part of publicly announced plans or programs:
		Total Number of Shares Purchased	Average Price paid per Share		Approximate Dollar Value of		Plan Expiration
					Shares that May Yet be
					Purchased under the Program
	November 16, 2012 - November 30, 2012	256,262	$	21.58	$	—	15-Aug-13
	December 1, 2012 - December 31, 2012	873,146	$	24.26	$	—	15-Aug-13
	Totals for 2012	1,129,408	$	23.65
	December 4, 2013 - December 11, 2013	600,000	$	13.18	$	—	14-May-14
	Totals for 2013	600,000

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Acacia’s provision for income taxes consists of the following for the years ended December 31, (in thousands):
		2014				2013				2012
	Current:
	Federal	$	—			$	—			$	—
	State taxes	289				113				281
	Foreign taxes	5,359				4,405				11,890
	Total current	5,648				4,518				12,171
	Deferred:
	Federal	(1,867		)		(26,151		)		10,085
	State taxes	131				(325		)		(196		)
	Total deferred	(1,736		)		(26,476		)		9,889
	Provision for (benefit from) income taxes	$	3,912			$	(21,958	)		$	22,060
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences and carryforwards that give rise to significant portions of deferred tax assets and liabilities consist of the following at December 31, 2014 and 2013 (in thousands):
		2014				2013
	Deferred tax assets:
	Net operating loss and capital loss carryforwards and credits	$	59,427			$	34,679
	Stock compensation	1,800				3,052
	Basis of investments in affiliates	1,437				867
	Accrued liabilities and other	409				387
	Unrealized loss on short-term investments	92				337
	State taxes	26				18
	Total deferred tax assets	63,191				39,340
	Valuation allowance	(35,927		)		(7,585		)
	Total deferred tax assets, net of valuation allowance	27,264				31,755
	Deferred tax liabilities:
	Fixed assets and intangibles	(27,157		)		(33,378		)
	Other	(107		)		(112		)
	Total deferred tax liabilities	(27,264		)		(33,490		)
	Net deferred tax assets (liabilities)	$	—			$	(1,735	)
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the federal statutory income tax rate and the effective income tax rate is as follows:
		2014			2013			2012
	Statutory federal tax rate - (benefit) expense	(35	)%		(35	)%		35	%
	State income and foreign taxes, net of federal tax effect	9	%		5	%		15	%
	Foreign tax credit	(8	)%		(6	)%		(15	)%
	Noncontrolling interests in operating subsidiaries	—	%		1	%		—	%
	Nondeductible permanent items	1	%		2	%		5	%
	Expired net operating loss carryforwards	—	%		2	%		—	%
	Valuation allowance	39	%		4	%		(13	)%
		6	%		(27	)%		27	%
Summary of Valuation Allowance [Table Text Block]	At December 31, 2013, the Company recorded valuation allowances for certain tax attribute carryforwards and other deferred tax assets due to uncertainty regarding future realizability, as follows:
		2013
	Capital loss carryforwards	$	1,562
	Net operating loss carryforwards	1,281
	Foreign tax credits	4,405
	Unrealized losses on short-term investments and other deferred tax assets	337
	Total valuation allowance	$	7,585
Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table Text Block]	ctivity related to the gross unrecognized tax benefits for the periods presented was as follows (in thousands):
	Balance at January 1, 2012	$	85
	Additions based on tax positions related to the current year	—
	Additions for tax positions related to prior years	772
	Additions resulting from the acquisition of ADAPTIX	1,270
	Reductions	—
	Balance at December 31, 2012	$	2,127
	Balance at December 31, 2013	$	2,127
	Balance at December 31, 2014	$	2,127

StockBased_Incentive_Plans_Tab

Stock-Based Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Stock Options Activity	The following table summarizes stock option activity for the Plans for the year ended December 31, 2014:
				Weighted-Average
		Options		Exercise		Remaining	Aggregate
				Price		Contractual Term	Intrinsic Value
	Outstanding at December 31, 2013	195,000		$	6.91
	Exercised	(45,000	)	$	4.6
	Outstanding at December 31, 2014	150,000		$	7.59	1 year	$	1,402,000
	Vested	150,000		$	7.59	1 year	$	1,402,000
	Exercisable at December 31, 2014	150,000		$	7.59	1 year	$	1,402,000
Nonvested Restricted Stock Activity	The following table summarizes nonvested restricted share activity for the year ended December 31, 2014:
		Nonvested		Weighted
		Restricted Shares		Average Grant Date Fair Value
	Nonvested restricted stock at December 31, 2013	1,237,000		$	28.23
	Granted	887,000		$	14.41
	Vested	(814,000	)	$	26.4
	Canceled	(292,000	)	$	24.55
	Nonvested restricted stock at December 31, 2014	1,018,000		$	18.71
Restricted Stock Units Activity	The following table summarizes restricted stock unit activity for the year ended December 31, 2014:
		Restricted		Weighted
		Stock Units		Average Grant Date Fair Value
	Nonvested restricted stock units outstanding at December 31, 2013	20,000		$	27.83
	Granted	33,000		$	14.33
	Vested	(20,000	)	$	22.99
	Nonvested restricted stock units outstanding at December 31, 2014	33,000		$	17.1
	Vested restricted stock units outstanding at December 31, 2014	74,000		$	21.14

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Minimum annual rental commitments for operating leases of continuing operations having initial or remaining noncancellable lease terms in excess of one year are as follows (in thousands):
	Years ending December 31,
	2015	$	1,564
	2016	1,595
	2017	1,557
	2018	1,612
	2019	1,669
	Thereafter	166
	Total minimum lease payments	$	8,163
Net assets of IP Fund [Table Text Block]	At December 31, 2014 and 2013, the Acacia IP Fund net assets and net loss were primarily comprised of the following (in thousands):
			2014			2013
	Cash and other assets		$	2,823		$	2,927
	Patents, net of accumulated amortization		967			1,373
	Investments - noncurrent		8,281			11,120
	Total assets		$	12,071		$	15,420
	Accrued expenses and contributions		$	1,876		$	2,437
	Total liabilities		1,876			2,437
	Net assets		$	10,195		$	12,983
			2014			2013
	Revenues		$	1,560		$	1,448
	Operating expenses		1,724			6,907
	Gain from operations		(164		)	(5,459		)
	Net loss in equity method investments		(1,807		)	(542		)
	Net loss		$	(1,971	)	$	(6,001	)

Quarterly_Financial_Data_Table

Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2013
QUARTERLY FINANCIAL DATA (unaudited) [Abstract]
Quarterly Financial Data	The following table sets forth unaudited consolidated statements of operations data for the eight quarters in the period ended December 31, 2014. This information has been derived from Acacia’s unaudited condensed consolidated financial statements that have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, include all adjustments, consisting of normal recurring adjustments, necessary for a fair statement of the information when read in conjunction with the audited consolidated financial statements and related notes thereto. Acacia’s quarterly results have been, and may in the future be, subject to significant fluctuations. As a result, Acacia believes that results of operations for interim periods should not be relied upon as any indication of the results to be expected in any future periods.
		Quarter Ended
		Mar. 31,			Jun. 30,			Sept. 30,			Dec. 31,			Mar. 31,			Jun. 30,			Sept. 30,			Dec. 31,
		2014			2014			2014			2014			2013			2013			2013			2013
		(Unaudited, in thousands, except share and per share information)
	Revenues	$	12,578		$	50,076		$	37,192		$	31,030		$	76,861		$	23,110		$	15,520		$	15,065
	Operating costs and expenses:
	Cost of revenues:
	Inventor royalties	951			10,694			4,667			4,358			18,481			5,610			2,353			3,280
	Contingent legal fees	1,527			7,077			7,663			7,296			15,032			4,024			2,547			3,181
	Litigation and licensing expenses - patents	8,994			10,820			9,592			8,208			9,648			9,918			10,870			8,899
	Amortization of patents	14,472			15,532			13,511			13,727			11,730			12,578			12,615			16,735
	Marketing, general and administrative expenses (including non-cash stock compensation expense)	11,693			13,181			11,636			12,044			13,844			13,184			18,235			13,988
	Research, consulting and other expenses - business development	992			1,003			1,208			637			1,031			726			730			742
	Other	—			—			1,548			—			—			—			3,506			—
	Total operating costs and expenses	38,629			58,307			49,825			46,270			69,766			46,040			50,856			46,825
	Operating income (loss)	(26,051		)	(8,231		)	(12,633		)	(15,240		)	7,095			(22,930		)	(35,336		)	(31,760		)
	Total other income (expense)	109			(196		)	(57		)	(451		)	1,290			400			280			161
	Income (loss) before (provision for) benefit from income taxes	(25,942		)	(8,427		)	(12,690		)	(15,691		)	8,385			(22,530		)	(35,056		)	(31,599		)
	Benefit from (provision for) income taxes	1,372			(4,689		)	(145		)	(450		)	(3,272		)	9,050			19,570			(3,390		)
	Net income (loss) including noncontrolling interests	(24,570		)	(13,116		)	(12,835		)	(16,141		)	5,113			(13,480		)	(15,486		)	(34,989		)
	Net (income) loss attributable to noncontrolling interests in operating subsidiaries	149			167			420			(103		)	—			977			(225		)	1,656
	Net income (loss) attributable to Acacia Research Corporation	$	(24,421	)	$	(12,949	)	$	(12,415	)	$	(16,244	)	$	5,113		$	(12,503	)	$	(15,711	)	$	(33,333	)
	Net income (loss) per common share attributable to Acacia Research Corporation:
	Basic income (loss) per share - As Adjusted(1)	$	(0.51	)	$	(0.27	)	$	(0.26	)	$	(0.34	)	$	0.1		$	(0.26	)	$	(0.33	)	$	(0.69	)
	Diluted income (loss) per share - As Adjusted(1)	$	(0.51	)	$	(0.27	)	$	(0.26	)	$	(0.34	)	$	0.1		$	(0.26	)	$	(0.33	)	$	(0.69	)
	Weighted-average number of shares outstanding, basic - As Adjusted(1)	48,329,375			48,543,334			48,806,334			48,944,914			47,859,774			48,008,998			48,330,149			48,415,684
	Weighted-average number of shares outstanding, diluted - As Adjusted(1)	48,329,375			48,543,334			48,806,334			48,944,914			48,104,242			48,008,998			48,330,149			48,415,684
		Quarter Ended
		Mar. 31,		Jun. 30,	Sept. 30,		Dec. 31,	Mar. 31,			Jun. 30,			Sept. 30,		Dec. 31,
		2014		2014	2014		2014	2013			2013			2013		2013
		(Unaudited, In thousands, except share and per share information)
	Basic income (loss) per share - As Reported(1)	N/A		N/A	N/A		N/A	$	0.11		$	(0.26	)	N/A		N/A
	Diluted income (loss) per share - As Reported(1)	N/A		N/A	N/A		N/A	$	0.11		$	(0.26	)	N/A		N/A
	Weighted-average number of shares outstanding, basic - As Reported(1)	N/A		N/A	N/A		N/A	47,859,774			48,008,998			N/A		N/A
	Weighted-average number of shares outstanding, diluted - As Reported(1)	N/A		N/A	N/A		N/A	48,354,444			48,008,998			N/A		N/A
	_______________________
	(1) - Revision of Prior Period Earnings (Loss) Per Share - Two-Class Method. In connection with the preparation of the Company’s Quarterly Report on Form 10-Q as of and for the three months ended September 30, 2013, the Company determined that its basic and diluted net income (loss) per share calculations should have been prepared using the “two-class method.” Under the two-class method, securities that participate in dividends are considered “participating securities.” The Company’s unvested restricted shares outstanding are considered “participating securities” because they include non-forfeitable rights to dividends.
	Pursuant to guidance set forth in Staff Accounting Bulletin (“SAB”) No. 99, “Materiality,” the Company concluded that the errors were not material to any of its prior period financial statements. Although the errors were immaterial to prior periods, the prior period financial statements presented herein were revised, in accordance with SAB No. 108, “Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements.”

Description_of_Business_Detail

Description of Business (Details) (USD $)	12 Months Ended			0 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 12, 2012
Description of Business [Line Items]
Payments to acquire businesses, gross	$0	$0	$150,000
ADAPTIX, Inc. [Member]
Description of Business [Line Items]
Payments to acquire businesses, gross				$150,000

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2014
Lag time in recognizing revenues from licensee's quarter	3 months
Minimum [Member]
Period after quarter end licensees report activity	30 days
Patents, useful life	1 year
Maximum [Member]
Period after quarter end licensees report activity	45 days
Patents, useful life	10 years

Summary_of_Significant_Account4

Summary of Significant Accounting Policies Concentrations (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Licensee 1 [Member] | Revenue, Rights Granted [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	22.00%	38.00%	21.00%
Licensee 1 [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	30.00%	60.00%
Licensee 2 [Member] | Revenue, Rights Granted [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	22.00%	16.00%	14.00%
Licensee 2 [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	17.00%	22.00%
Licensee 3 [Member] | Revenue, Rights Granted [Member]
Concentration Risk [Line Items]
Concentration risk, percentage			10.00%
Licensee 3 [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%
Licensee 4 [Member] | Revenue, Rights Granted [Member]
Concentration Risk [Line Items]
Concentration risk, percentage			10.00%
Licensees in foreign jurisdictions [Member] | Revenue, Rights Granted [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	43.00%	24.00%	43.00%

Summary_of_Significant_Account5

Summary of Significant Accounting Policies Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2014
Furniture and Fixtures [Member] | Minimum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	3
Furniture and Fixtures [Member] | Maximum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	5
Computer Hardware and Software [Member] | Minimum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	3
Computer Hardware and Software [Member] | Maximum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	5
Leasehold Improvements [Member] | Minimum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	2
Leasehold Improvements [Member] | Maximum [Member]
Property and Equipment [Line Items]
Estimated useful lives, years	5

Summary_of_Significant_Account6

Summary of Significant Accounting Policies Earnings per share (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Net income (loss) attributable to Acacia Research Corporation	($16,244)	($12,415)	($12,949)	($24,421)	($33,333)	($15,711)	($12,503)	$5,113	($66,029)	($56,434)	$59,453
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic									0	0	-1,889
Net Income (Loss) Available to Common Stockholders, Basic									-66,755	-56,945	57,564
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted									0	0	-1,876
Payments of Dividends									-25,039	-18,633	0
Dividends attributable to common stockholders under the two class method									24,313	18,122	0
Net Income (Loss) Available to Common Stockholders, Diluted									($66,755)	($56,945)	$57,577
Weighted-average number of shares outstanding, basic - As Adjusted(1)	48,944,914	48,806,334	48,543,334	48,329,375	48,415,684	48,330,149	48,008,998	47,859,774	48,658,088	48,155,832	47,251,061
Weighted Average Number Diluted Shares Outstanding Adjustment									0	0	333,059
Weighted-average number of shares outstanding, diluted - As Adjusted(1)	48,944,914	48,806,334	48,543,334	48,329,375	48,415,684	48,330,149	48,008,998	48,104,242	48,658,088	48,155,832	47,584,120
Basic income (loss) per common share	($0.34)	($0.26)	($0.27)	($0.51)	($0.69)	($0.33)	($0.26)	$0.10	($1.37)	($1.18)	$1.22
Diluted income (loss) per common share	($0.34)	($0.26)	($0.27)	($0.51)	($0.69)	($0.33)	($0.26)	$0.10	($1.37)	($1.18)	$1.21
Anti-dilutive equity-based incentive awards excluded from the computation of diluted income (loss) per share									27,760	27,760	30,812

Summary_of_Significant_Account7

Summary of Significant Accounting Policies Impact of revision (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Net income (loss) attributable to Acacia Research Corporation	($16,244,000)	($12,415,000)	($12,949,000)	($24,421,000)	($33,333,000)	($15,711,000)	($12,503,000)	$5,113,000	($66,029,000)	($56,434,000)	$59,453,000
Net Income (Loss) Available to Common Stockholders, Basic									-66,755,000	-56,945,000	57,564,000
Net Income (Loss) Available to Common Stockholders, Diluted									-66,755,000	-56,945,000	57,577,000
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – basic - As Reported											47,251,061
Weighted-average number of shares outstanding, basic - As Adjusted(1)	48,944,914	48,806,334	48,543,334	48,329,375	48,415,684	48,330,149	48,008,998	47,859,774	48,658,088	48,155,832	47,251,061
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – diluted - As Reported											48,060,647
Weighted-average number of shares outstanding, diluted - As Adjusted(1)	48,944,914	48,806,334	48,543,334	48,329,375	48,415,684	48,330,149	48,008,998	48,104,242	48,658,088	48,155,832	47,584,120
Basic net income (loss) per common share, As Reported											1.26
Basic income (loss) per common share	($0.34)	($0.26)	($0.27)	($0.51)	($0.69)	($0.33)	($0.26)	$0.10	($1.37)	($1.18)	$1.22
Diluted net income (loss) per common share - As Reported											$1.24
Diluted income (loss) per common share	($0.34)	($0.26)	($0.27)	($0.51)	($0.69)	($0.33)	($0.26)	$0.10	($1.37)	($1.18)	$1.21

Shortterm_Investments_Details

Short-term Investments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, amortized cost	$58,819	$130,971
Available-for-sale securities, gross unrealized gains	2	21
Available-for-sale securities, gross unrealized losses	-263	-975
Available-for-sale securities, fair value	58,558	130,017
Available-for-sale Securities, Gross Realized Gains		1,174	31
Available-for-sale Securities, Gross Realized Losses	2,188	981	555
Proceeds from Sale and Maturity of Marketable Securities	$182,115	$239,370	$319,811
Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment Maturity Date		31-Dec-14
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment Maturity Date	31-Dec-15	31-Dec-15

Shortterm_Investments_Marketab

Short-term Investments Marketable Securities (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$58,819	$130,971
Available-for-sale Securities, Gross Unrealized Gain	2	21
Available-for-sale Securities, Gross Unrealized Loss	263	975
Available-for-sale Securities	$58,558	$130,017

Furniture_and_Equipment_Detail

Furniture and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation expense	$304,000	$236,000	$149,000
Property, Plant and Equipment, Disposals	330,000	130,000
Gain (Loss) on Disposition of Property Plant Equipment	$71,000	$12,000

Furniture_and_Equipment_Summar

Furniture and Equipment Summary of Property and Equipment (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property and Equipment [Line Items]
Furniture and fixtures	$761	$783
Computer hardware and software	650	687
Leasehold improvements	144	306
Property and equipment, gross	1,555	1,776
Less: accumulated depreciation and amortization	-1,055	-1,010
Furniture and equipment, net	$500	$766

Accounts_Payable_and_Accrued_E2

Accounts Payable and Accrued Expenses (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accounts payable	$121	$128
Payroll and other employee benefits	1,481	1,039
Accrued vacation	806	813
Accrued legal expenses - patent	8,410	5,900
Accrual for court ordered attorneys fees	1,548	0
Accrued consulting and other professional fees	1,530	2,948
Accrued distribution to noncontrolling interest	0	504
Other accrued liabilities	964	223
Accounts payable and accrued expenses	$14,860	$11,555

Patents_Details

Patents (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Patents [Line Items]
Patents, net	$286,636,000	$288,432,000
Patents, weighted average useful life	6 years
Payments to acquire intangible assets	42,746,000	25,061,000	178,260,000
Accrued patent acquisition related payments	16,700,000	4,000,000
Accelerated amortization expense	1,247,000	592,000	10,574,000
Accelerated amortization expense (termination)	2,702,000	1,747,000	3,034,000
Impairment of Intangible Assets (Excluding Goodwill)	3,497,000	4,619,000	0
Minimum [Member]
Patents [Line Items]
Patents, useful life	1 year
Acquired Finite Lived Intangible Asset, Useful Life	3 years
Maximum [Member]
Patents [Line Items]
Patents, useful life	10 years
Acquired Finite Lived Intangible Asset, Useful Life	10 years
Patents [Member]
Patents [Line Items]
Gross carrying amount - patents	453,201,000	400,755,000
Accumulated amortization - patents	166,565,000	112,323,000
Patents, net	$286,636,000	$288,432,000
Patents [Member] | Minimum [Member]
Patents [Line Items]
Patents, useful life	1 year
Patents [Member] | Maximum [Member]
Patents [Line Items]
Patents, useful life	9 years

Patents_Cost_and_Accumulated_A

Patents Cost and Accumulated Amortization (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Patents [Line Items]
Patent cost, disposals	$3,000	$3,500	$5,500
Accumulated amortization, disposals	298	1,753	2,466
Proceeds from Sale of Intangible Assets	$3,500	$1,000	$2,792

Patents_Future_Amortization_Ex

Patents Future Amortization Expense (Details) (USD $)	Dec. 31, 2014
Patents [Abstract]
2015	$52,019,000
2016	49,332,000
2017	48,245,000
2018	44,117,000
2019	38,679,000
After Year Five	$54,244,000

Acquisition_Details

Acquisition (Details) (ADAPTIX, Inc. [Member], USD $)	0 Months Ended	12 Months Ended
	Jan. 12, 2012	Dec. 31, 2014
	patents
	countries
ADAPTIX, Inc. [Member]
Business Acquisition [Line Items]
Acquired entity - cash	$10,000,000
Number of issued and pending patents in portfolio of acquired entity	230
Number of countries where acquire entity holds issued and pending patents	13
Payments to acquire businesses, gross	$160,000,000
Patents, useful life	10 years	10 years

Acquisition_Purchase_Price_All

Acquisition Purchase Price Allocation (Details) (USD $)	0 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Jan. 12, 2012	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		30,149	$30,149
ADAPTIX, Inc. [Member]
Business Acquisition [Line Items]
Fair value of net tangible assets acquired	10,000
Intangible assets acquired - patents	150,000
Goodwill	30,149
Net deferred income tax liability	-30,149
Total	160,000
Patents, useful life	10 years	10 years
Patents, future annual amortization expense per year	$15,000

Acquisition_Acquisition_Deferr

Acquisition Acquisition Deferred Tax (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 12, 2012
Business Acquisition [Line Items]
Estimated tax rate	-35.00%	-35.00%	35.00%
ADAPTIX, Inc. [Member]
Business Acquisition [Line Items]
Book basis of intangible assets acquired - patents				$150,000,000
Tax basis of intangible assets acquired - patents				0
Change from book and tax basis of intangible assets acquired - patents				-150,000,000
Estimated net operating loss carryforwards - ADAPTIX				0
Tax basis of estimated net operating loss carryforwards - ADAPTIX				63,860,000
Change from book and tax basis of estimated net operating loss carryforwards - ADAPTIX				63,860,000
Net deferred tax liability - pretax				-86,140,000
Estimated tax rate				35.00%
Deferred tax asset, acquisition				($30,149,000)

Acquisition_Pro_Forma_Informat

Acquisition Pro Forma Information (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012
Business Combinations [Abstract]
Pro forma revenues	$250,727
Pro forma total operating costs and expenses	170,953
Pro forma operating income	79,774
Pro forma interest and investment income	937
Pro forma income from operations before provision for income taxes	80,711
Pro forma provision for income taxes	-22,060
Pro forma net income including noncontrolling interests	58,651
Pro forma net (income) loss attributable to noncontrolling interests	164
Pro forma net income attributable to Acacia Research Corporation	$58,815
Pro forma income per common share attributable to Acacia Research Corporation [Abstract]
Pro forma basic earnings per share	$1.24
Pro forma diluted earnings per share	$1.22
Pro forma weighted average number of shares outstanding, basic	47,251,061
Pro forma weighted average number of shares outstanding, diluted	48,060,647

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	0 Months Ended	3 Months Ended	12 Months Ended
	Feb. 21, 2012	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 15, 2013	Nov. 16, 2012
Stockholders Equity [Line Items]
Gross proceeds from the sale of common stock	$225,000,000
Sale of common stock, price per share	$36.75
Proceeds from Issuance of Common Stock			0	0	218,961,000
Stock repurchase program, authorized amount						70,000,000	100,000,000
Dividends declared, per share			$0.50
Common stock dividends declared, quarterly		$0.13	$0.13
Sale of common stock, value			-25,039,000	-18,633,000
Payments of Dividends			25,039,000	18,633,000	0
Dividends, payment date		30-Mar-15
Dividends, record date		2-Mar-15
Common Stock [Member]
Stockholders Equity [Line Items]
Sale of common stock, shares				0	6,122,449
Sale of common stock, value				$0	$6,000

Stockholders_Equity_Repurchase

Stockholders' Equity Repurchases of Common Stock (Details) (USD $)	0 Months Ended		1 Months Ended		12 Months Ended
	Dec. 11, 2013	Nov. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2012
Stockholders' Equity Note [Abstract]
Treasury stock, shares acquired	600,000	256,262		873,146	600,000	1,129,408
Treasury stock acquired, average price paid per share	$13.18	$21.58	$24.26		$23.65
Stock repurchase program, remaining authorized repurchase amount			$0	$0		$0

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]
Income tax benefit from release of valuation allowance			($10,651,000)
Operating loss carryforwards, federal	118,715,000
Operating loss carryforwards, state	129,632,000
Deferred tax assets, valuation allowance	35,927,000	7,585,000
Federal NOL annual utilization limit	14,100,000
Net operating losses, unrecognized excess tax benefits, federal	1,928,000
Net operating losses, unrecognized excess tax benefits, state	37,771,000
Foreign withholding taxes	5,159,000	4,605,000	11,890,000
Excess tax benefits from stock-based compensation	0	-1,398,000	13,210,000
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	2,713,000	1,398,000	13,210,000
Foreign tax credits, additional paid in capital benefit	29,877,000
Foreign tax credits utilized for financial statement purposes	20,313,000
Effective Income Tax Rate Reconciliation, Percent	6.00%	-27.00%	27.00%
Effective tax rate excluding valuation allowance	-33.00%	31.00%	40.00%
Unrecognized tax benefits	2,127,000	2,127,000	2,127,000	85,000
unrecognized tax benefits primarily associated with state taxes	85,000
Domestic Tax Authority [Member]
Income Taxes [Line Items]
Net operating losses included in deferred tax assets	0
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Net operating losses included in deferred tax assets	441,000
Capital Loss Carryforward Related to Business Acquisition [Member] | Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Operating Loss Carryforwards	$29,318,000

Income_Taxes_Provision_for_Tax

Income Taxes Provision for Taxes (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current:
Federal									$0	$0	$0
State taxes									289	113	281
Foreign taxes									5,359	4,405	11,890
Total current									5,648	4,518	12,171
Deferred:
Federal									-1,867	-26,151	10,085
State taxes									131	-325	-196
Total deferred									-1,736	-26,476	9,889
(Provision) benefit for income taxes	$450	$145	$4,689	($1,372)	$3,390	($19,570)	($9,050)	$3,272	$3,912	($21,958)	$22,060

Income_Taxes_Deferred_Taxes_De

Income Taxes Deferred Taxes (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Net operating loss and capital loss carryforwards and credits	$59,427	$34,679
Stock compensation	1,800	3,052
Basis of investments in affiliates	1,437	867
Accrued liabilities and other	409	387
Unrealized loss on short-term investments	92	337
State taxes	26	18
Total deferred tax assets	63,191	39,340
Deferred tax liabilities:
Fixed assets and intangibles	-27,157	-33,378
Other	-107	-112
Deferred Tax Liabilities, Gross	-27,264	-33,490
Net deferred tax liabilities	0	-1,735
Less: valuation allowance	-35,927	-7,585
Net deferred taxes	$27,264	$31,755

Income_Taxes_Income_Tax_Rate_D

Income Taxes Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Statutory federal tax rate	-35.00%	-35.00%	35.00%
State income and foreign taxes, net of federal tax effect	9.00%	5.00%	15.00%
Foreign tax credit	-8.00%	-6.00%	-15.00%
Noncontrolling interests in operating subsidiaries	0.00%	1.00%	0.00%
Non deductible permanent items	1.00%	2.00%	5.00%
Expired net operating loss carryforwards	0.00%	2.00%	0.00%
Valuation allowance	39.00%	4.00%	-13.00%
Total	6.00%	-27.00%	27.00%

Income_Taxes_Gross_Unrecognize

Income Taxes Gross Unrecognized Tax Benefit (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$2,127	$2,127	$2,127	$85
Additions based on tax positions related to the current year	0
Additions for tax positions related to prior years	772
Additions resulting from the acquisition of ADAPTIX	1,270
Reductions	$0

Income_Taxes_Valuation_allowan

Income Taxes Valuation allowance (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Capital loss carryforwards, valuation allowance	$1,562
Operating Loss Carryforwards, Valuation Allowance	1,281
Foreign tax credits, valuation allowance	4,405
Unrealized losses on short-term investments and other deferred tax assets, valuation allowance	337
Valuation Allowances and Reserves, Balance	$7,585

StockBased_Incentive_Plans_Det

Stock-Based Incentive Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2009	Dec. 31, 2008
Share-based Compensation Arrangement by Share-based Payment Award
Ownership percent of voting stock	10.00%
Aggregate intrinsic value of options exercised	$518,000	$2,024,000	$1,796,000
Number of shares of common stock reserved for issuance	3,500,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Weighted average grant date fair value of restricted stock granted	$14.41	$24.31	$32.17
Aggregate fair value of restricted stock vested	21,490,000	22,317,000	28,865,000
Total unrecognized compensation expense for nonvested awards	15,012,000
Weighted average period over which unrecognized compensation expense will be recognized	1 year 8 months
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Weighted average grant date fair value of restricted stock granted	$14.33	$0	$29.39
Aggregate fair value of restricted stock vested	460,000	469,000	363,000
Total unrecognized compensation expense for nonvested awards	$475,000
Weighted average period over which unrecognized compensation expense will be recognized	1 year 8 months
2007 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Increase in number of shares available, percentage of outstanding shares on last trading day of prior December				2.00%
Number of shares available for grant	0				560,000
Discretionary Option Grant Program [Member] | Nonstatutory Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of fair market value on grant date, minimum exercise price	85.00%
Stock Issuance Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of fair market value on grant date, minimum exercise price	100.00%
2002 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Increase in number of shares available, percentage of outstanding shares on last trading day of prior December	3.00%
Maximum number of shares available increase per year	500,000
Aggregate shares available for issuance	20,000,000
2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares available for grant	4,750,000
Number of shares of common stock reserved for issuance	3,243,000
Less than 10% [Member] | Discretionary Option Grant Program [Member] | Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of fair market value on grant date, minimum exercise price	100.00%
10% or More [Member] | Discretionary Option Grant Program [Member] | Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of fair market value on grant date, minimum exercise price	110.00%

StockBased_Incentive_Plans_Sto

Stock-Based Incentive Plans Stock Options (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Outstanding at December 31, 2012	195,000
Exercised	-45,000
Outstanding at December 31, 2013	150,000
Vested	150,000
Exercisable at December 31, 2013	150,000
Outstanding at December 31, 2012, weighted average exercise price	$6.91
Exercised, weighted average exercise price	$4.60
Outstanding at December 31, 2013, weighted average exercise price	$7.59
Vested, weighted average exercise price	$7.59
Exercisable, weighted average exercise price	$7.59
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	1 year
Outstanding at December 31, 2013, aggregate, intrinsic value	$1,402,000
Vested, aggregate intrinsic value	1,402,000
Exercisable, aggregate intrinsic value	$1,402,000

StockBased_Incentive_Plans_Non

Stock-Based Incentive Plans Nonvested Restriced Stock (Details) (Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested at December 31, 2012	1,237,000
Granted	887,000
Vested	-814,000
Canceled	-292,000
Nonvested at December 31, 2013	1,018,000	1,237,000
Nonvested, weighted average grant date fair value at December 31, 2011	$28.23
Granted, weighted average grant date fair value	$14.41	$24.31	$32.17
Vested, weighted average grant date fair value	$26.40
Canceled, weighted average grant date fair value	$24.55
Nonvested, weighted average grant date fair value at December 31, 2012	$18.71	$28.23

StockBased_Incentive_Plans_Non1

Stock-Based Incentive Plans Nonvested Restricted Stock Units (Details) (Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested at December 31, 2012	20,000
Granted	33,000
Vested	-20,000
Nonvested at December 31, 2013	33,000	20,000
Vested outstanding	74,000
Nonvested, weighted average grant date fair value at December 31, 2011	$27.83
Granted, weighted average grant date fair value	$14.33	$0	$29.39
Vested, weighted average grant date fair value	$22.99
Nonvested, weighted average grant date fair value at December 31, 2012	$17.10	$27.83
Vested outstanding, weighted average grant date fair value	$21.14

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingencies Disclosure [Abstract]
Rent expense									$1,523,000	$1,312,000		$898,000
Other	0	1,548,000	0	0	0	3,506,000	0	0	1,548,000	3,506,000	0
Loss Contingencies, Amount Requested from Defendants									2,800,000
Partners' capital, authorized	250,000,000								250,000,000
Cash and other assets, IP Fund	2,823,000				2,927,000				2,823,000	2,927,000
Patents, net of accumulated amortization, IP Fund	967,000				1,373,000				967,000	1,373,000
Investments, IP Fund	8,281,000				11,120,000				8,281,000	11,120,000
Total assets, IP Fund	12,071,000				15,420,000				12,071,000	15,420,000
Accrued expenses and contributions, IP Fund	1,876,000				2,437,000				1,876,000	2,437,000
Total liabilities, IP Fund	1,876,000				2,437,000				1,876,000	2,437,000
Net assets, IP Fund	10,195,000				12,983,000				10,195,000	12,983,000
Revenues, IP Fund									1,560,000	1,448,000
IP Fund, Operating expenses									1,724,000	6,907,000
IP Fund, Gain from Operations									-164,000	-5,459,000
IP Fund, Net Loss in Equity Method Investment									-1,807,000	-542,000
IP Fund, Net Loss									($1,971,000)	($6,001,000)

Commitments_and_Contingencies_2

Commitments and Contingencies Operating Leases (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Year:
2014	$1,564
2015	1,595
2016	1,557
2017	1,612
2018	1,669
Thereafter	166
Total minimum lease payments	$8,163

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Cash Flow Information [Abstract]
Estimated federal income taxes paid	$0	$3,000,000	$0
Income Taxes Receivable		3,251,000
Accrued distribution to noncontrolling interest	0	504,000
Cash paid for state income taxes	172,000	516,000	771,000
Foreign withholding taxes	$5,159,000	$4,605,000	$11,890,000

Quarterly_Financial_Data_Detai

Quarterly Financial Data (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
QUARTERLY FINANCIAL DATA (unaudited) [Abstract]
Revenues	$31,030	$37,192	$50,076	$12,578	$15,065	$15,520	$23,110	$76,861
Inventor royalties	4,358	4,667	10,694	951	3,280	2,353	5,610	18,481	20,670	29,724	26,028
Contingent legal fees	7,296	7,663	7,077	1,527	3,181	2,547	4,024	15,032	23,563	24,784	24,651
Litigation and licensing expenses - patents	8,208	9,592	10,820	8,994	8,899	10,870	9,918	9,648	37,614	39,335	21,591
Amortization of patents	13,727	13,511	15,532	14,472	16,735	12,615	12,578	11,730	57,242	53,658	39,019
Marketing, general and administrative expenses (including non-cash stock compensation expense)	-12,044	-11,636	-13,181	-11,693	-13,988	-18,235	-13,184	-13,844	-48,554	-59,229	-54,083
Research, consulting and other expenses - business development	637	1,208	1,003	992	742	730	726	1,031	3,840	3,251	4,943
Other	0	1,548	0	0	0	3,506	0	0	1,548	3,506	0
Total operating costs and expenses	46,270	49,825	58,307	38,629	46,825	50,856	46,040	69,766	193,031	213,487	170,315
Operating income (loss)	-15,240	-12,633	-8,231	-26,051	-31,760	-35,336	-22,930	7,095	-62,155	-82,931	80,412
Total other income (expense)	-451	-57	-196	109	161	280	400	1,290	-595	2,131	937
Income (loss) from operations before (provision for) benefit from income taxes	-15,691	-12,690	-8,427	-25,942	-31,599	-35,056	-22,530	8,385	-62,750	-80,800	81,349
(Provision) benefit for income taxes	-450	-145	-4,689	1,372	-3,390	19,570	9,050	-3,272	-3,912	21,958	-22,060
Net income (loss) including noncontrolling interests in operating subsidiaries	-16,141	-12,835	-13,116	-24,570	-34,989	-15,486	-13,480	5,113	-66,662	-58,842	59,289
Net (income) loss attributable to noncontrolling interests in operating subsidiaries	103	-420	-167	-149	-1,656	225	-977	0	-633	-2,408	-164
Net income (loss) attributable to Acacia Research Corporation	($16,244)	($12,415)	($12,949)	($24,421)	($33,333)	($15,711)	($12,503)	$5,113	($66,029)	($56,434)	$59,453
Basic income (loss) per share - As Adjusted(1)	($0.34)	($0.26)	($0.27)	($0.51)	($0.69)	($0.33)	($0.26)	$0.10	($1.37)	($1.18)	$1.22
Diluted income (loss) per share - As Adjusted(1)	($0.34)	($0.26)	($0.27)	($0.51)	($0.69)	($0.33)	($0.26)	$0.10	($1.37)	($1.18)	$1.21
Weighted-average number of shares outstanding, basic - As Adjusted(1)	48,944,914	48,806,334	48,543,334	48,329,375	48,415,684	48,330,149	48,008,998	47,859,774	48,658,088	48,155,832	47,251,061
Weighted-average number of shares outstanding, diluted - As Adjusted(1)	48,944,914	48,806,334	48,543,334	48,329,375	48,415,684	48,330,149	48,008,998	48,104,242	48,658,088	48,155,832	47,584,120
Earnings (loss) per share, basic, as previously reported							($0.26)	$0.11
Earnings (loss) per share, diluted as previously reported							($0.26)	$0.11
Weighted average number of shares, basic, as previously reported							48,008,998	47,859,774
Weighted average number of shares, diluted, as previously reported							48,008,998	48,354,444