ASP.NET Authorize attribute and Admin user role

Using Authorize attribute i may specify roles which is allowed to access the resources.

[Authorize(Roles="User")]

But if i have admin user which is allowed to go to any resource i need specify this one as well

[Authorize(Roles="User, Administrator")]

But may be there is some way i can say somehow that Administrator allowed to go anywhere and not to specify this one in Authorize attribute?

So i mean if somewhere in code(on controller or on action) would be this [Authorize(Roles="User")] it means that Administrator role allowed to go there as well.

Or may be i may set it to all Authorize roles dynamically how when application start?

Any ideas?

UPDATED:

Currently i have one admin controller with Authorize attribute [Authorize(Role="Administrator")] and i have some actions in some another controllers with attributes [Authorize(Role="User")] so i will need to add "Administrator" there as well if i didn't find better solution.