for all I care

for all (one) cares

One does not care (if something were to happen). The phrase always precedes or follows some hypothetical situation. You can starve to death for all I care. I am not giving you any more of my leftovers.
See also: all, care
Farlex Dictionary of Idioms.

for all I care

I don't care if (something happens). For all I care, the whole city council can go to the devil. They can all starve for all I care.
See also: all, care
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

for all —

in spite of —.
1989 Independent For all their cruel, corrupt and reckless vices, the Maharajahs were worshipped as gods by tens of thousands of their subjects.
See also: all
Farlex Partner Idioms Dictionary
See also:
  • for all (one) cares
  • for all I, you, etc. care
  • I could care less
  • could care less
  • care not a groat
  • take care
  • see what I care
  • see if I care
  • See if I care!
  • SIIC