Viewing Inline Documentation
Documentation is shown in the Documentation pop-up window:
When you explicitly invoke code completion, then quick documentation for an entry selected in the suggestion list can be displayed automatically. The behavior of quick documentation lookup is configured in the Show documentation popup in field on the Code Completion page of the Settings/Preferences dialog.
View documentation for a symbol at caret
On the main menu, choose.
Provided that the checkbox Show quick doc on mouse move in the editor settings is selected, just move your mouse pointer over the desired symbol.