Telling anyone except a lawyer (or similar professional) without the necessary legal agreements counts as 'disclosure' of your idea and can invalidate any future patent application you make. In addition, if you can't prove when you had an idea, it's very hard to prove that it was yours if it ever gets stolen.
Using Innvolve allows you to record and communicate your idea safely in a secure online folio. Every change you make is recorded and time-stamped on our secure servers. When you need to share aspects of the idea you can provide others limited access to your folio and Innvolve will generate legally binding confidentiality agreements automatically.