No, you do not have to file a California state return if you have no other CA income. Public
Law 104-95 (P.L. 104-95) prevents any
state from taxing income from certain pensions and deferred compensation plans
paid to individuals who are not residents or domiciliaries of that state. If you are an Idaho resident, the income is taxable to Idaho only, regardless of where you lived when you earned the compensation or who the payee is.