Despite that I have ticked the "auto-display documentation" and tried inputting different numbers in "ms" box - I still have to press CTRL+Q to see the documentation. How to make it work?

Also if I click CTRL+Q to show documentation pop up manually - the pop up is too small. Can I make it bigger by default to contain all the text?

IntelliJ IDEA 2018.1 (Ultimate Edition) Build #UI-181.4203.550
Linux Mint 18.3 Sylvia, Cinnamon 64-bit



It seems there is a bug. If you open the settings via the gear icon and tick the
show toolbarit will work again (at least I was able to reproduce it and this fixed it for me).I don't have issues with the size (I'm on mac) using IntelliJ IDEA 2018.1.2 (Ultimate Edition) Build #IU-181.4668.14.
You can create an issue on their issue tracker here: https://youtrack.jetbrains.com/issues/IDEA.
For more info about reporting issues, see: https://www.jetbrains.com/help/idea/reporting-issues.html
Update for IntelliJ 2018.2:
(more info here: https://blog.jetbrains.com/idea/2018/05/intellij-idea-2018-2-early-access-program-is-open)