Umbrella insurance provides insurance gap coverage.
You may have auto, home or motorcycle insurance for liability protection but gaps can still be present in your coverage, and that can become very costly in the event of a claim against you. If there is a loss, it is very possible for you to exhaust your policy limits, an umbrella insurance policy is available for such a situation and will cover those additional costs. When lawsuits are involved the cost can become extremely high. I am sure you have seen those billboards on the highway showing what lawyers were able to secure for their clients out of a lawsuit.
Without an umbrella insurance policy anything in excess of your regular insurance policy limits would not be covered.