the (very) idea!
An exclamation of shocked disapproval regarding something someone said or did. They thought I would just go along with their plan to cut my pay while taking on more responsibility. The idea! The very idea—how dare you suggest something so horrible!
the (very) iˈdea!
(old-fashioned, spoken) used to express surprise or disapproval at the way somebody behaves: She expected me to pay for everything. The idea!