I was going to recommend this previous thread that had a somewhat similar issue and specifically discussion about the virtualenv requirement…when I realized it was you on that thread, which would explain how that option got enabled 
In any case, our advice (e.g. mine) there still applies, so I won’t repeat all that again here. The reason the option is enabled is, presumably, because you followed our recommendation there to turn it on.
To summarize, always installing packages in a venv/conda env is a recommended best practice for both pip and conda. Many Python devs (including me) adheres to it, but it is especially important for newer users, to avoid problems like the one you experienced in your previous issue and make it much easier to recover from them. I believe you’ll find the space and time cost of it to be very small next to what it can save you in terms of having to deal with dependency conflicts, botched installations and other issues. However, you do really want to disable it, you can run the following:
pip config set global.require-virtualenv false
To launch idle, or anything else in the environment, just activate the environment and then start idle from the command line as you usually would do (i.e. python -m idlelib).