Is it safe to store a file of personal details online?

I was thinking of putting a master list of important personal information online related to identity and logins, financial stuff, etc. But I was concerned how stupid of an idea this might or might not be.

I'm not really worried about someone targeting me personally, more of general data mining type stuff where people are looking for keywords like SSN or credit card numbers, etc., for identity theft and other nefarious purposes.

Although I'm also a little concerned about someone just getting my login information for wherever it's stored and finding it that way.

My basic questions are, how should I do this; should I not do it at all? I want this information stored and backed up someplace accessible from wherever I am and available if I lose/forget it. Is this low risk/high risk? How do the common services hold up from this point of view (Skydrive, Google, Evernote, etc.)