Support with evidence record in detail (8)
I believe the answer is:
document
I believe this is a double definition.
'support with evidence' is the first definition.
('document' can be a synonym of 'support with evidence')
'record in detail' is the second definition.
('document' can be a synonym of 'record in detail')
(Other definitions for document that I've seen before include "Paper, record" , "Evidence" , "Will, for example" , "Piece of writing, of an official nature perhaps" , "Don cut me (anag)" .)