In every detail (2,3,6)
I believe the answer is:
to the letter
'in every detail' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for to the letter that I've seen before include "how should tenant's rent be paid?" , "Following every detail" , "Exact in every detail" , "From the tenant, presumably" , "correct in every detail" .)