I have a use case that does not seem to be fulfilled by Single Logout.  Perhaps it is just the particular product that we are using for our federation.

In the use case, a user has logged into multiple service providers.  They allow their session to timeout at the Identity Provider (either from not using the services at the IdP or by leaving their browser session idle) and then issue a Single Logout request from one of the service providers. 

Should the Single Logout process complete despite the fact that the session has timed out at the Identity Provider?

Thanks