Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 58,678	$ 57,359
Trading securities - debt	88,963	93,843
Trading securities - equity	10,470	17,140
Accounts receivable	621	511
Prepaid expenses and other current assets	3,653	2,912
Total current assets	162,385	171,765
Long-term restricted cash	35,000	35,000
Investment at fair value (Note 5)	1,387	1,500
Patents, net of accumulated amortization	12,550	7,814
Leased right-of-use assets	1,395	1,264
Other non-current assets	1,004	818
Total assets	213,721	218,161
Current liabilities:
Accounts payable	3,136	1,765
Accrued expenses and other current liabilities	4,376	7,265
Accrued compensation	1,127	507
Royalties and contingent legal fees payable	2,070	2,178
Total current liabilities	10,709	11,715
Series A warrant liabilities	2,610	3,568
Series A embedded derivative liabilities	21,682	17,974
Series B warrant liabilities	6,231	0
Long-term lease liabilities	1,395	1,264
Other long-term liabilities	583	593
Total liabilities	43,210	35,114
Commitments and contingencies (Note 6)
Series A redeemable convertible preferred stock, par value $0.001 per share; stated value $100 per share; 350,000 shares authorized, issued and outstanding as of March 31, 2020 and December 31, 2019, respectively; aggregate liquidation preference of $35,000 as of March 31, 2020 and December 31, 2019, respectively	8,720	8,089
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; 300,000,000 shares authorized; 49,813,443 and 50,370,987 shares issued and outstanding as of March 31, 2020 and December 31, 2019, respectively	50	50
Treasury stock, at cost, 3,496,726 and 2,919,828 shares as of March 31, 2020 and December 31, 2019, respectively	(40,586)	(39,272)
Additional paid-in capital	651,441	652,003
Accumulated deficit	(450,947)	(439,656)
Total Acacia Research Corporation stockholders' equity	159,958	173,125
Noncontrolling interests	1,833	1,833
Total stockholders' equity	161,791	174,958
Total liabilities, redeemable convertible preferred stock, and stockholders' equity	$ 213,721	$ 218,161