Detective managed to retire without getting to rock bottom (5)
I believe the answer is:
nadir
'to rock bottom' is the definition.
(a nadir is something's lowest point)
'detective managed to retire without' is the wordplay.
'detective' becomes 'di' (Detective Inspector abbreviation).
'managed' becomes 'ran' (both can mean organised or was in charge of).
'to retire' says the letters should be written backwards (retire can mean to go back).
'without' means one lot of letters goes inside another.
'ran' written backwards gives 'nar'.
'di' inserted within 'nar' is 'NADIR'.
'getting' is the link.
(Other definitions for nadir that I've seen before include "The lowest point of anything" , "Point of greatest despair" , "Drain into the lowest point (5)" , "Very bottom, farthest from zenith" , "most unsuccessful point" .)