The future minimum lease payments as of December 31, 2018 were as follows (amounts in thousands): 2019 $ 68,443 2020 49,874 2021 38,446 2022 28,496 2023 21,473 Thereafter 66,518 Total future minimum lease payments $ 273,250 FPD FCD Total (Amounts in thousands) Balance as of December 31, 2017 $ 801,509 $ 416,679 $ 1,218,188 Currency translation and other (11,370) (9,178) (20,548) Balance as of December 31, 2018 $ 790,139 $ 407,501 $ 1,197,640 Currency translation and other (3,509) (1,121) (4,630) Balance as of December 31, 2019 $ 786,630 $ 406,380 $ 1,193,010 December 31, 2019 December 31, 2018 Useful Life (Years) Ending Gross Amount Accumulated Amortization Ending Gross Amount Accumulated Amortization (Amounts in thousands, except years) Finite-lived intangible assets: Engineering drawings(1) 10-22 $ 89,490 $ (78,854 ) $ 89,796 $ (75,239 ) Existing customer relationships(2) 5-10 81,844 (53,468) 82,235 (47,016) Patents 9-16 26,132 (26,132 ) 26,251 (26,136 ) Other 4-40 92,920 (40,149) 88,138 (37,145) $ 290,386 $ (198,603 ) $ 286,420 $ (185,536 ) Indefinite-lived intangible assets(3) $ 90,607 $ (1,585) $ 91,251 $ (1,585) The following table provides information about our intangible assets for the years ended December 31, 2019 and 2018: The changes in the carrying amount of goodwill for the years ended December 31, 2019 and 2018 are as follows: (1) Engineering drawings represent the estimated fair value associated with specific acquired product and component schematics. (2) Existing customer relationships acquired prior to 2011 had a useful life of five years. (3) Accumulated amortization for indefinite-lived intangible assets relates to amounts recorded prior to the implementation date of guidance issued in ASC 350. 74 5. GOODWILL AND OTHER INTANGIBLE ASSETS Year ending December 31,