idle  means not in action or at work...
because 

http://images.arcadja.com/aldor_janos_laszlo-falusi_idill~OM4c6300~10988_20101218_169_101.jpg
it is supposed to remind us a delightful place...
idyll
 
is that place... from the greek poems...

idyll or idyl (play /ˈdəl/ or /ˈɪdəl/; from Greek εἰδύλλιον - eidullion, "short poem"[1]) is a short poem, descriptive of rustic life, written in the style of Theocritus' short pastoral poems, the Idylls.
now used like this:

"Idyllic
location in the heart of the western lakes."
or "Idyllic lakeside setting is the perfect venue for your short break, whether you are golfing or just relaxing.".

therefore, a place for doing nothing...

"
An example of    idle  is
to stand in front of a store with a group of friends just hanging out."


Unlike Homer, Theocritus did not engage in heroes and warfare. His idylls are limited to a small intimate world, and describe scenes from everyday life. Later imitators include the Roman poets Virgil and Catullus, Italian poet Leopardi, and the English poet Alfred, Lord Tennyson (Idylls of the King). Goethe called his poem Hermann and Dorothea - which Schiller considered the very climax in Goethe's production - an idyll.
read more here.