There were no changes in the carrying amount of goodwill for continuing operations as of December 31, 2019 and 2018. The carrying values of goodwill for CTU and AIU were $45.9 million and $41.4 million, respectively, as of December 31, 2019 and 2018.

We performed our annual impairment analysis of goodwill as of October 1, 2019 and determined that neither of our reporting units were impaired as of October 1, 2019.

In assessing the fair value for CTU and AIU, we performed a qualitative assessment to determine if we believe it is more likely than not that our reporting unit’s carrying values exceed their respective fair values. When performing the qualitative assessment, management first considered events and circumstances that may affect the fair value of the reporting unit to determine whether it is necessary to perform the quantitative impairment test. Management focused on the significant inputs, including its projections of revenue growth, operating expense leverage and the discount rate used in the prior year assessment, and any events or circumstances that could affect the significant inputs. These events and circumstances included, but were not limited to, financial performance, future expectations of financial performance, legal, regulatory, contractual, competitive, economic, political, business or other factors, and industry and market considerations, such as a deteriorating operating environment or increased competition. Management evaluated all events and circumstances, including positive or mitigating factors, that could affect the significant inputs used to determine fair value. Additionally, management evaluated its most recent quantitative assessment to determine by how much the previous fair value exceeded the carrying value for each indefinite-lived intangible asset.

The determination of estimated fair value of each reporting unit requires significant estimates and assumptions, and as such, these fair value measurements are categorized as Level 3 per ASC Topic 820. These estimates and assumptions primarily include, but

are not limited to, the discount rate, terminal growth rates, operating cash flow projections and capital expenditure forecasts. Due to the inherent uncertainty involved in deriving those estimates, actual results could differ from those estimates. We evaluate the merits of each significant assumption used, both individually and in the aggregate, to determine the fair value of each reporting unit for reasonableness.

As of December 31, 2019 and 2018, the net book value of other intangible assets are as follows (dollars in thousands):

	As of December 31, 2019		As of December 31, 2018
Non-amortizable intangible assets:
Accreditation rights	$	1,000	$	1,000
CTU trade name		6,900		6,900
Net book value, non-amortizable intangible assets:	$	7,900	$	7,900

As of December 31, 2019, net intangible assets include certain accreditation rights and trade names that are considered to have indefinite useful lives and, in accordance with FASB ASC Topic 350—Intangibles—Goodwill and Other, are not subject to amortization but rather reviewed for impairment on at least an annual basis by applying a fair-value-based test. Additionally, we have an intangible asset related to our former Le Cordon Bleu trade name that has been fully amortized.

We performed our annual impairment testing of indefinite-lived intangible asset balances as of October 1, 2019 utilizing the qualitative assessment approach and concluded that no indicators existed that would suggest that it is more likely than not that the assets would be impaired. We continue to monitor the operating results and revenue projections related to our CTU trade name and accreditation rights on a quarterly basis for signs of possible declines in estimated fair value.