Robert S. Silberman joined the Company in 2001. He served as President and Chief Executive Officer from 2001 to 2003, as Chairman of the Board and Chief Executive Officer from 2003 to 2013, as Executive Chairman of the Board from 2013 to 2023, and currently serves as Chairman of the Board. Earlier in his career, Mr. Silberman served as President and Chief Operating Officer of CalEnergy Company, a subsidiary of Berkshire Hathaway, Inc. (NYSE: BRK). He is a Managing Director of Equity Group Investments and serves as the Chairman of the Board of Par Pacific Holdings, Inc. (NYSE: PARR). Mr. Silberman was appointed by President George H.W. Bush as the U.S. Assistant Secretary of the Army, and served in other senior positions in the U.S. Department of Defense from 1989 to 1993. He is a member of the Council on Foreign Relations.