If you're going to leave it overnight, you need to put it in the refrigerator.
The lower temperature will retard the development of yeast in the dough. This will guard against over-proofing.
If you leave it on the counter the yeast will continue to develop unabated. When yeast feeds on the sugars it produces CO2. Eventually the yeast will deplete all the sugars in the dough. When that happens CO2 will no longer be produced. No gas bubbles, no rise--that's when the dough had been over proofed.