“General assets” means all property, real, personal or otherwise, not specifically mortgaged, pledged, deposited or otherwise encumbered for the security or benefit of specified persons or a limited class or classes of persons, and as to such specifically encumbered property the term includes all such property or its proceeds in excess of the amount necessary to discharge the sums secured thereby. Assets held in trust or on deposit for the security or benefit of all policyholders or all policyholders and creditors in the United States are deemed general assets.