Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Disaggregation of Revenue [Table Text Block]

Revenues were comprised of the following for the periods presented (in thousands):



	2018		2017
Paid-up Revenue Agreements	$	100,496	$	59,020
Recurring Revenue Agreements	13,040		6,382
Other Settlements	3,470		—
Sales	14,500		—
	$	131,506	$	65,402

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

Financial assets and liabilities measured at fair value on a recurring basis were as follows (in thousands):



	Level 1		Level 2		Level 3
Assets as of December 31, 2018:
Trading securities - debt	$	—	$	33,642	$	—
Trading securities - equity	3,012		—		—
Investment at fair value - warrants (Note 6)	—		2,064		—
Investment at fair value - common stock (Note 6)	5,395		—		—
Total recurring fair value measurements as of December 31, 2018	$	8,407	$	35,706	$	—

Assets as of December 31, 2017:
Investments at fair value (Note 6)	$	—	$	—	$	104,754

Liabilities as of December 31, 2018:
Profits interest units	$	—	$	591	$	—
Liabilities as of December 31, 2017:
Profits interest units	$	—	$	—	$	3,041

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The fair values of stock options granted during the periods presented were estimated using the Black-Scholes option-pricing model, based on the following weighted-average assumptions:



	For the Years Ended
	December 31, 2018	December 31, 2017

Risk-free interest rate	2.26%	1.77%
Term	4.37	4.37
Volatility	51%	51%
Dividend yield	—%	—%

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:



	2018			2017
Numerator (in thousands):
Basic and Diluted
Net income (loss) attributable to Acacia Research Corporation	$	(105,029	)	$	22,180
Undistributed earnings allocated to participating securities	—			(33		)
Net income (loss) attributable to common stockholders – basic and diluted	$	(105,029	)	$	22,147

Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders – basic	49,969,062			50,495,119
Effect of potentially dilutive securities:
Common stock options and restricted stock units	—			196,893
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders – diluted	49,969,062			50,692,012
Basic and diluted net loss per common share	$	(2.10	)	$	0.44
Anti-dilutive equity-based incentive awards excluded from the computation of diluted loss per share	3,129,719			4,425,187