ILC detector R{\&}D and design studies.

Starting from the precision physics program of the ILC, the talk will outline the corresponding necessary detector performance in order to do this physics. Based on this performance I will outline what detector R{\&}D needs to be done to realize such a detector, give a status of the worldwide R{\&}D activities, what still needs to be in the future and describe the status of the current detector concept studies that are being pursued worldwide.