The big thing about Idaho is it is winner take all if you get 50% plus. If Cruz can get to 50% in Idaho, he could actually come out ahead in delegates on the night even if he loses the rest of the states because all the rest are proportional.
Also, another big thing to watch is the floor in some of these states. Some are at 20%, others at 15%. Does not bode well for Rubio and Kasich in some of these states.