Detention Oversight, Not Expansion Act or the DONE Act This bill prohibits the Department of Homeland Security (DHS) from using any federal funds to construct or expand immigration detention facilities and requires additional oversight of such facilities. The DHS Inspector General shall conduct various oversight activities into immigration detention facilities, including (1) periodic unannounced inspections; (2) audits to ensure compliance with various legal requirements; and (3) investigations into issues such as deaths in custody, detainee access to medical and mental health care, and sexual assault and harassment. DHS may not continue a contract with any facility deemed less than adequate in two of the most recent inspector general inspections, audits, or investigations. The Office for Civil Rights and Civil Liberties within DHS shall (1) investigate civil rights and civil liberties complaints in immigration detention facilities, and (2) periodically release on a public website data about such complaints and investigations. The bill requires various reports to Congress, including a DHS plan for decreasing the number of immigration detention beds and implementing community-based alternatives to detention.