Two U.S. senators on Tuesday questioned whether the Justice Department has been aggressive enough in prosecuting misconduct at the largest banks and asked the department to turn over information on how it determines punishments.

Sherrod Brown, a Democrat who chairs a Senate Banking subcommittee, and Chuck Grassley, the top Republican on the Senate Judiciary Committee, said they were worried certain Wall Street banks enjoyed “too big to fail” status in enforcement policy, resulting in penalties that were disproportionately low.