Goodwill by Segment The carrying amounts of goodwill by segment as of September 30, 2021 and December 31, 2020 are included in the table below. Foreign currency fluctuations are included within other adjustments. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | December 31, 2020 | | | | | | | | September 30, 2021 | | In millions | Goodwill | | Accumulated Impairment Losses | | Total | | Additions | | Impairment | | Other | | Goodwill | | Accumulated Impairment Losses | | Total | | Banking | $ | 1,772 | | | $ | (101) | | | $ | 1,671 | | | $ | 1,633 | | | $ | — | | | $ | — | | | $ | 3,405 | | | $ | (101) | | | $ | 3,304 | | | Retail | 643 | | | (34) | | | 609 | | | 38 | | | — | | | (2) | | | 679 | | | (34) | | | 645 | | | Hospitality | 404 | | | (23) | | | 381 | | | 11 | | | — | | | (2) | | | 413 | | | (23) | | | 390 | | | Telecommunications & Technology | 187 | | | (11) | | | 176 | | | — | | | — | | | — | | | 187 | | | (11) | | | 176 | | | Total goodwill | $ | 3,006 | | | $ | (169) | | | $ | 2,837 | | | $ | 1,682 | | | $ | — | | | $ | (4) | | | $ | 4,684 | | | $ | (169) | | | $ | 4,515 | |
Identifiable Intangible Assets NCR's purchased intangible assets, reported in intangibles, net in the Condensed Consolidated Balance Sheets, were specifically identified when acquired, and are deemed to have finite lives. The gross carrying amount and accumulated amortization for NCR’s identifiable intangible assets were as set forth in the table below. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Amortization
Period
(in Years) | | September 30, 2021 | | December 31, 2020 | | In millions | | Gross Carrying Amount | | Accumulated Amortization | | Gross Carrying Amount | | Accumulated Amortization | | Identifiable intangible assets | | | | | | | | | | | Reseller & customer relationships | 1 - 20 | | $ | 1,092 | | | $ | (370) | | | $ | 740 | | | $ | (324) | | | Intellectual property | 2 - 8 | | 1,054 | | | (455) | | | 531 | | | (418) | | | Customer contracts | 8 | | 89 | | | (89) | | | 89 | | | (89) | | | Tradenames | 1 - 10 | | 131 | | | (79) | | | 77 | | | (74) | | | Total identifiable intangible assets | | | $ | 2,366 | | | $ | (993) | | | $ | 1,437 | | | $ | (905) | |
The aggregate amortization expense for identifiable intangible assets for the following periods is: | | | | | | | | | | | | | | | | | | | In millions | Three months ended September 30, 2021 | | Nine months ended September 30, 2021 | | Remainder of 2021 (estimated) | | Amortization expense | $ | 45 | | | $ | 88 | | | $ | 45 | |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For the years ended December 31 (estimated) | | In millions | | 2022 | | 2023 | | 2024 | | 2025 | | 2026 | | Amortization expense | | $ | 175 | | | $ | 171 | | | $ | 162 | | | $ | 150 | | | $ | 140 | |
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