| Cover - shares | 9 Months Ended | |
| Sep. 30, 2022 | Nov. 07, 2022 | |
| Cover [Abstract] | ||
| Document Type | 10-Q/A | |
| Amendment Flag | true | |
| Amendment Description | Correct the certifications | |
| Document Quarterly Report | true | |
| Document Transition Report | false | |
| Document Period End Date | Sep. 30, 2022 | |
| Document Fiscal Period Focus | Q3 | |
| Document Fiscal Year Focus | 2022 | |
| Current Fiscal Year End Date | --12-31 | |
| Entity File Number | 1-37721 | |
| Entity Registrant Name | Acacia Research Corporation | |
| Entity Central Index Key | 0000934549 | |
| Entity Tax Identification Number | 95-4405754 | |
| Entity Incorporation, State or Country Code | DE | |
| Entity Address, Address Line One | 767 Third Avenue | |
| Entity Address, Address Line Two | 6th Floor | |
| Entity Address, City or Town | New York | |
| Entity Address, State or Province | NY | |
| Entity Address, Postal Zip Code | 10017 | |
| City Area Code | (332) | |
| Local Phone Number | 236-8500 | |
| Title of 12(b) Security | Common Stock | |
| Trading Symbol | ACTG | |
| Security Exchange Name | NASDAQ | |
| Entity Current Reporting Status | Yes | |
| Entity Interactive Data Current | Yes | |
| Entity Filer Category | Non-accelerated Filer | |
| Entity Small Business | true | |
| Entity Emerging Growth Company | false | |
| Entity Shell Company | false | |
| Entity Common Stock, Shares Outstanding | 43,540,276 |
