play animation on top of animation

I have a basic idle to walk animation and would like to add "open door" animation that can be run while an idle or walking animation is playing.

I tried to solve this problem by moving open door animation to another layer in animator controller and setting blending mode to override and it seemed to work but when the "open door" animation finishes, it goes back to the idle or walk animation instantly making it look weird.

Please help me.. I've been struggling with this problem for about a week.