 In 1965–1966, Idris was chief of staff of the Strategic Reserve Command (KOSTRAD), and had an important role in the overthrow of Sukarno and the rise of General Suharto to power.Nevertheless, by 1980 Idris had a falling out with Suharto and he was part of group of senior Indonesian retired generals and politicians to sign a petition highlighting their concerns against Suharto increasing authoritarian rule.This group was later known as the Petisi 50 group, highlighting the number of its signatories.