Consolidated Balance Sheets Statement (USD $) In Thousands, unless otherwise specified	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Cash and Cash Equivalents	$ 310,663	$ 102,515
Short-term investments	6,514	0
Accounts receivable	32,560	7,987
Prepaid expenses and other current assets	927	1,679
Total current assets	350,664	112,181
Property and equipment, net of accumulated depreciation	232	135
Patents, net of accumulated amortization	14,665	19,803
Investments - noncurrent	1,956	2,001
Other assets	467	664
Total assets	367,984	134,784
Current Liabilities [Abstract]
Accounts payable and accrued expenses	7,201	7,099
Royalties and contingent legal fees payable	37,050	12,760
Total current liabilities	44,251	19,859
Other liabilities	608	1,072
Total liabilities	44,859	20,931
Commitments and contingencies (Note 5)
Stockholders' Equity [Abstract]
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; 42,873,001 and 36,029,068 shares issued and outstanding as of September 30, 2011 and December 31, 2010, respectively	43	36
Additional paid-in capital	384,283	197,026
Accumulated comprehensive loss	(1,913)	0
Accumulated deficit	(60,896)	(86,191)
Total Acacia Research Corporation stockholders' equity	321,517	110,871
Noncontrolling interests in operating subsidiaries	1,608	2,982
Total stockholders' equity	323,125	113,853
Total liabilities and stockholders' equity	$ 367,984	$ 134,784