I haven't tried suppressing a page, I usually suppress a section. Since you want to suppress a group 'above' the details section, what I would do it devise a test to see if the Recovery is negative.  Once it has been printed, CR doesn't hide, and it sounds like you want to suppress only if Details a-c are negative, which implies that a might be negative and c won't need...So you need to test to determine if the recovery is negative, say in teh group header, before you do any printing of details, then you can suppress the group correctly.