Sekou Wiggs contributed 13 points and dished out five assists. Chad Sherwood and Arkadiy Mkrtychyan added 12 points apiece, and Victor Sanders had 10 for Idaho (5-5), which shot 52.3 percent from the floor and gave coach Don Verlin a program record with 102 wins.
The Vandals held Walla Walla, an NAIA team, to just 26.4 percent shooting and enjoyed a 48-24 rebounding advantage.
Walla Walla sank the opening bucket, a 3-pointer from Ethan Osias, but quickly fell behind as Idaho responded with an 18-5 run to take control with a lead that was never challenged. The Vandals took a 49-18 advantage into the break and continued to pull away in the second half.
Jordan Spady led Walla Walla with 11 points.