Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 73,285,000	$ 128,809,000
Short-term investments - debt securities	93,756,000	33,642,000
Short-term investments - equity securities	831,000	3,012,000
Accounts receivable	23,964,000	32,884,000
Prepaid expenses and other current assets	3,686,000	3,125,000
Total current assets	195,522,000	201,472,000
Investments at fair value	5,483,000	7,459,000
Investment - other	8,195,000	8,195,000
Patents, net	9,681,000	6,587,000
Other assets	216,000	236,000
Total assets	219,097,000	223,949,000
Current liabilities:
Accounts payable and accrued expenses	11,448,000	8,347,000
Accrued Patent Acquisition Related Payments, Current	3,750,000	0
Royalties and contingent legal fees payable	16,149,000	22,688,000
Total current liabilities	31,347,000	31,035,000
Other liabilities	916,000	1,674,000
Total liabilities	32,263,000	32,709,000
Commitments and contingencies (Note 6)
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; 49,656,067 and 49,639,319 shares issued and outstanding as of March 31, 2019 and December 31, 2018, respectively	50,000	50,000
Treasury stock, at cost, 2,919,828 shares as of March 31, 2019 and December 31, 2018	(39,272,000)	(39,272,000)
Additional paid-in capital	651,148,000	651,156,000
Accumulated deficit	(426,925,000)	(422,541,000)
Total Acacia Research Corporation stockholders' equity	185,001,000	189,393,000
Noncontrolling interests in operating subsidiaries	1,833,000	1,847,000
Total stockholders' equity	186,834,000	191,240,000
Total liabilities and stockholders' equity	$ 219,097,000	$ 223,949,000