  The ILD detector is proposed for an electron-positron collider with collision
centre-of-mass energies from 90~\GeV~to about 1~\TeV. It has been developed
over the last 10 years by an international team of scientists with the goal to
design and eventually propose a fully integrated detector, primarily for the
International Linear Collider, ILC.
  In this report the fundamental ideas and concepts behind the ILD detector are
discussed and the technologies needed for the realisation of the detector are
reviewed.
  The document starts with a short review of the science goals of the ILC, and
how the goals can be achieved today with the detector technologies at hand.
After a discussion of the ILC and the environment in which the experiment will
take place, the detector is described in more detail, including the status of
the development of the technologies foreseen for each subdetector. The
integration of the different sub-systems into an integrated detector is
discussed, as is the interface between the detector and the collider. This is
followed by a concise summary of the benchmarking which has been performed in
order to find an optimal balance between performance and cost. To the end the
costing methodology used by ILD is presented, and an updated cost estimate for
the detector is presented. The report closes with a summary of the current
status and of planned future actions.
