The committee prepared the secret 6,200 report after a five-year investigation of the Central Intelligence Agencys "extended" interrogation practices, including waterboarding.
In April, it voted to release 500 pages of the report, pending review by the CIA and the president.
Sen. Dianne Feinstein, who chairs the committee, said in a statement that "the report exposes brutality that stands in stark contrast to our values as a nation. It chronicles a stain on our history that must never again be allowed to happen. This is not what Americans do."