| Schedule of goodwill |
The table below summarizes the changes in the carrying amount of goodwill by reportable segment: | | | | | | | | | | | | | | Graduate Program Segment | | Alternative Credential Segment | | Total | | (in thousands) | Balance as of December 31, 2017 | $ | — |
| | $ | 71,988 |
| | $ | 71,988 |
| Foreign currency translation adjustments | — |
| | (10,136 | ) | | (10,136 | ) | Balance as of December 31, 2018 | — |
| | 61,852 |
| | 61,852 |
| Goodwill recognized in connection with business combination | — |
| | 425,346 |
| | 425,346 |
| Impairment charge (current and cumulative) | — |
| | (70,379 | ) | | (70,379 | ) | Foreign currency translation adjustments | — |
| | 1,531 |
| | 1,531 |
| Balance as of December 31, 2019 | $ | — |
| | $ | 418,350 |
| | $ | 418,350 |
|
|
| Schedule of amortizable intangible assets |
Amortizable intangible assets, net consisted of the following as of: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | December 31, 2019 | | December 31, 2018 | | Estimated Average Useful Life (in years) | | Gross Carrying Amount | | Accumulated Amortization | | Net Carrying Amount | | Gross Carrying Amount | | Accumulated Amortization | | Net Carrying Amount | | | | (in thousands) | Capitalized technology | 3-5 | | $ | 142,712 |
| | $ | (41,106 | ) | | $ | 101,606 |
| | $ | 68,291 |
| | $ | (16,945 | ) | | $ | 51,346 |
| Capitalized content development | 4-5 | | 167,758 |
| | (54,736 | ) | | 113,022 |
| | 79,725 |
| | (31,662 | ) | | 48,063 |
| University client relationships | 9-10 | | 110,344 |
| | (12,419 | ) | | 97,925 |
| | 25,616 |
| | (4,269 | ) | | 21,347 |
| Trade names and domain names | 5-10 | | 26,462 |
| | (5,940 | ) | | 20,522 |
| | 18,793 |
| | (2,944 | ) | | 15,849 |
| Total amortizable intangible assets, net | | | $ | 447,276 |
|
| $ | (114,201 | ) |
| $ | 333,075 |
|
| $ | 192,425 |
|
| $ | (55,820 | ) |
| $ | 136,605 |
|
|
| Schedule of estimated future amortization expense for amortizable intangible assets |
As of December 31, 2019, the estimated future amortization expense for amortizable intangible assets placed in service is as follows (in thousands): | | | | | 2020 | $ | 75,955 |
| 2021 | 69,605 |
| 2022 | 55,520 |
| 2023 | 36,403 |
| 2024 | 19,512 |
| Thereafter | 45,357 |
| Total | $ | 302,352 |
|
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