This map shows the rapid growth in the number of countries with explicit deposit guarantee programs. When a government creates this type of program they have to choose who will govern it: the ministry of finance (i.e. direct government control), the central bank, or a specialised entity, like the United State's Deposit Insurance Corporation. Specialised deposit insurers may be indirectly accountable to some combination of the government, the central bank, or other actors. Generally, they are not accountable to only one, so we can think of them as having delegated powers.
For more information see: Gandrud (2011).