NC taxation of non resident pension

I own property in North Carolina, but I am a non-resident.  None of my retirement (IRAs, etc.) income comes from North Carolina sources.  But it seems that the only retirement income I can shield from NC taxation is that which comes under the Bailey Settlement.  Which makes it appear that NC can tax the retirement income of a non-resident with no retirement income from NC sources.  Is that true?  When I say "retirement income", I am speaking of retirement benefits, not income from the property I own in North Carolina.