I log everything I do. I even try to estimate an equivalent mileage if I do something like play a pickup game of soccer. The reasoning is that my mileage calendar isn't a trophy, it is a way for me to track wear and tear and prevent myself from doing too much.
However, unless I am hurt, I wouldn't really ever do a run under maybe 5 miles.
I put full details onto my log of every workout (workout done and splits) so it is easy for me to go back and try to figure out what seems to be working and what doesn't. The total at the end of each week really is just for tracking total volume to keep myself from doing too much and getting hurt.