How is “that's an idea” used?

In Christopher Robin (2018), one line is: “That's an idea, Piglet.”

Which movie is “that's an idea” from?

The clip at the top of this page is from Christopher Robin (2018).

That's an idea, Piglet.

6 作品で登場 · 1 本目

イディオム

used to reply in a positive way to a suggestion that sb has made

くだけた · 6 本の映画に登場

that's an idea!
used to reply in a positive way to a suggestion that sb has made
Hey, that's an idea! And we could get a band, as well.

定義：Oxford Advanced Learner's Dictionary 第 9 版