92 The Company continually evaluates its accounts receivables for potential collection risks particularly those resulting from sales to government- owned or government-supported healthcare facilities in certain countries as payment may be dependent upon the financial stability and creditworthiness of those countries’ national economies. The Company continually evaluates all governmental receivables for potential collection risks associated with the availability of government funding and reimbursement practices. The Company believes the current reserves related to all governmental receivables are adequate and that this concentration of credit risk will not have a material adverse impact on its financial position or liquidity. The Company maintains cash deposits in excess of government-provided insurance limits. Such cash deposits are exposed to loss in the event of nonperformance by financial institutions. Substantially all of the Company’s trade receivables are due from public and private entities involved in the healthcare industry. Due to the large size and diversity of the Company’s customer base, concentrations of credit risk with respect to trade receivables are limited. The Company does not normally require collateral. The Company is exposed to credit loss in the event of nonperformance by financial institutions with which it conducts business. However, this loss is limited to the amounts, if any, by which the obligations of the counterparty to the financial instrument contract exceed the obligations of the Company. The Company also minimizes exposure to credit risk by dealing with a diversified group of major financial institutions. In fiscal year 2019, the Company recorded a charge of $30 million to write down the carrying value of certain intangible assets in the Surgery unit. In fiscal year 2018, the Company recorded charges of $58 million to write down the value of fixed assets, primarily in the Diabetes Care unit, as well as charges of $81 million to write down the carrying value of certain intangible and other assets in the Biosciences unit. The amounts recognized in 2019 and 2018 were recorded to adjust the carrying amount of assets to the assets' fair values, which were estimated, based upon a market participant's perspective, using either Level 2 inputs, including quoted prices for similar assets, or Level 3 inputs, including values estimated using the income approach. All other instruments measured by the Company at fair value, including derivatives and contingent consideration liabilities, are immaterial to the Company's consolidated balance sheets. Long-term debt is recorded at amortized cost. The fair value of long-term debt is measured based upon quoted prices in active markets for similar instruments, which are considered Level 2 inputs in the fair value hierarchy. The fair value of long-term debt was $19.2 billion and $18.8 billion at September 30, 2019 and 2018, respectively. The fair value of the current portion of long-term debt was $1.3 billion and $1.9 billion at September 30, 2019 and 2018, respectively. Short-term investments are held to their maturities and are carried at cost, which approximates fair value. The short-term investments consist of instruments with maturities greater than three months and less than one year. Notes to Consolidated Financial Statements — (Continued) Becton, Dickinson and Company Table of Contents Nonrecurring Fair Value Measurements Concentration of Credit Risk