How did Detente end the Cold War?

Detente, as applied to cold war, is a term used to signify
the easing of tension between communist and non-communist countries. In this way detente
did not just "end the cold war", it is "the end of cold
war".

I think the detente itself occurred because of the
realization by each of the communist and non-communist block that the other party could
not really do much to harm the interest of the other. To some extent the realization by
each party of the limitation of the their own political ideology must have also helped,
by impressing upon them to set their own house in order rather than trying to impose
their ideologies on other countries.

Also, the realization
of enormous cost of cold war in terms of resources wasted on arms race, indecisive wars
to settle disputes of other countries, and wasted opportunities for economic betterment
of their own people must have been a decisive factor in softening the stance of opposing
groups.