you are no idiot

someone said this to me.
i know that is the same as "you are not an idiot" but does that statement have a sarcastic flavor to it, or did the speaker literally just meant im not an idiot?

"You are no idiot." means "You're not an idiot."

I don't think it's sarcastic unless there's something else in the context that suggests it.

I think we'd need to have more context around the "you are no idiot" phrase to beter guess the meaning.