Open Dev Tools (Click the menu "…" button, More Tools, Developer Tools) then click "Security" then "View Certificate".
What annoys me most is that Firefox refuses to show you the certificate if it fails to validate, which makes figuring out validation errors more painful.
You can view it in Firefox as well: Advanced -> Add exception -> View
Or, as I just noticed, when you click on the error code (SEC_ERROR_EXPIRED_CERTIFICATE for example) it'll show you the raw certificate.
(I still wish it could also just be in the normal spot.)
What details would they realistically look at, anyways? If the certificate validates, that's an automated check of most of the interesting bits. But the first thing in my dialog, for example, is the subject, which is garbage for many DV certs. Then there's the difference between CN and subjectAltName…
The browser does this for you. Chrome (and all major browsers) have a certificate validation that parses the hostname in the certificate and compares it to the site you are on.
Checking certificate details manually is primarily useful for troubleshooting. It serves little to no security benefit for 99% of users.