Making a character's idle animation loop. (model and animation created in blender)

Hi. I've been using unity and blender for about 2 weeks now. I ran into some trouble in my 3rd person platformer game. i made my model in blender and at this point have only created his idle animation. After hours of struggling i got his animation to play in game using a character controller. What i can't figure out is trying to make it loop. I see the loop check box in the inspector tab when i click on the animation BUT everything is grayed out and i cant alter anything within the tab. this only happens with animations the inspector tab works fine with other things. if anyone could help me here is would mean allot to me. Thank you in advance :)