ISIS funds itself, in part, by looting Syria's ancient treasures. On Tuesday, CBS News got the first look at ISIS' own records which were scooped up in a raid by U.S. special operations forces.

When ISIS financial kingpin Abu Sayyaf was killed by U.S. Special Forces last May, American soldiers made a startling discovery: hundreds of precious antiquities stored in his compound.

On Tuesday, newly discovered declassified documents show for the first time just how deeply ISIS relies on smuggling antiquities to fund its terror.

Abu Sayyaf was the group's top antiquities dealer. Receipts also show him to be a careful record keeper. Treasury officials told us transactions totaled hundreds of millions of dollars.