.7 billion , which is related to ten reporting units , each of which consists of a group of markets with similar economic characteristics . the estimated fair value of each of our ten reporting units exceeded the carrying value as of december 31 , 2017 . to determine the fair value of non-amortizable intangible assets , we primarily use a discounted cash flow model applying the relief-from-royalty method . we concluded that the fair value of our non-amortizable intangible assets exceeded the carrying value