E. I. du Pont de Nemours and Company Notes to the Consolidated Financial Statements (continued) Total estimated amortization expense for the next five fiscal years is as follows: (In millions) 2019 $ 1,228 2020 $ 1,211 2021 $ 1,199 2022 $ 1,182 2023 $ 1,078 Short-term borrowings and capital lease obligations (In millions) December 31, 2018 December 31, 2017 Commercial paper $ 1,847 $ 1,436 Other loans - various currencies 16 28 Long-term debt payable within one year 268 1,314 Capital lease obligations payable within one year 29 1 Total short-term borrowings and capital lease obligations $ 2,160 $ 2,779 The estimated fair value of the company's short-term borrowings, including interest rate financial instruments, was determined using Level 2 inputs within the fair value hierarchy, as described in Note 1 and Note 21. Based on quoted market prices for the same or similar issues, or on current rates offered to the company for debt of the same remaining maturities, the fair value of the company's short-term borrowings and capital lease obligations was $2,160 million and $2,780 million at December 31, 2018 and 2017, respectively. F-51 The following tables summarize the company's short-term borrowings and capital lease obligations and long-term debt: NOTE 15 - SHORT-TERM BORROWINGS, LONG-TERM DEBT AND AVAILABLE CREDIT FACILITIES