X- I/A Table of Contents FIRST DATA CORPORATION NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS (Continued) The estimated future aggregate amortization expense for the next five years is as follows: fear ended December 31, On millions) Amount 2015 $ 751 2016 588 2017 486 2018 419 2019 365 The Company tests contract and conversion costs for recoverability on an annual basis by comparing the remaining expected undistountix1 cash flows under the contract to the net book value. Any assets that are determined to be unrecoverable are written down to their fair value. In addition to this annual test, these assets and all other long lived assets are tested for impairment upon an indicator of potential impairment. Assets and Liabilities Measured at Fair Value on a Recurring Basis Fair value is deflated by accounting guidance as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The Company uses the hierarchy pr scribed in the accounting guidance for fair value measurements. bassi upon the available inputs to the valuation and the degree to which they are observable or not observable in the market. The Company maximizes the use of relevant observable inputs and minimizes the use of unobservable inputs. The three levels in the hierarchy are as follows: • Level I Inputs—Quoted prices (unadjusted) for identical assets or liabilities in active markets that are accessible as of the measurement date. • Level 2 Inputs—Inputs other than quoted prices within Level 1 that am observable either directly or indirectly, including but not limited to quoted prices in markets that are not active, quoted prices in active markets for similar assets or liabilities, and observable inputs other than quoted prices such as interest rates or yield curves. • Level 3 Inputs—Unobservable inputs reflecting the Company's own assumptions about the assumptions that