If you have no intention of acting on them, I don't think it's a big deal. I think we all, regardless of issues or lack of them, sometimes picture such a situation on stairs, a cliff, a bridge...whatever.

Suicidal ideation is when suicide seems preferable to whatever you're facing in life....usually an end to pain, whether physical or emotional, doesn't matter. Anything to get rid of the constant, unending pain. Of course, it isn't the anwer, but that is the thinking behind it, and I can't say I've never been in that frame of mind.