Intangible Assets
 12 Months Ended
Sep. 30, 2018
Intangible Assets, Net (Excluding Goodwill) [Abstract]  
Intangible Assets
Intangible Assets
The Company's intangible assets consist of the following for the periods indicated:
(In millions)

Technology
and Patents
 
Customer
Relationships
and Other
Intangibles
 
Trademarks
and Trade Names
 
Total
Balance as of September 30, 2018 (Successor)
 
 
 
 
 
 
 
Finite-lived intangible assets:
 
 
 
 
 
 
 
Cost
$
959

 
$
2,157

 
$
43

 
$
3,159

Accumulated amortization
(135
)
 
(124
)
 
(3
)
 
(262
)
Finite-lived intangible assets, net
824

 
2,033

 
40

 
2,897

 
 
 
 
 
 
 
 
Indefinite-lived intangible assets
5

 
—

 
332

 
337

Intangible assets, net
$
829

 
$
2,033

 
$
372

 
$
3,234

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Balance as of September 30, 2017 (Predecessor)
 
 
 
 
 
 
 
Finite-lived intangible assets:
 
 
 
 
 
 
 
Cost
$
1,427

 
$
2,196

 
$
—

 
$
3,623

Accumulated amortization
(1,411
)
 
(2,091
)
 
—

 
(3,502
)
Finite-lived intangible assets, net
16

 
105

 
—

 
121

 
 
 
 
 
 
 
 
Indefinite-lived intangible assets:
 
 
 
 
 
 
 
Cost
—

 
—

 
545

 
545

Accumulated impairment
—

 
—

 
(355
)
 
(355
)
Indefinite-lived intangible assets, net
—

 
—

 
190

 
190

Intangible assets, net
$
16

 
$
105

 
$
190

 
$
311

Amortizable technology and patents have useful lives that range between 1 year and 10 years with a weighted average remaining useful life of 4.9 years. IPR&D activities are considered indefinite-lived until projects are completed or abandoned. Customer relationships have useful lives that range between 1 year and 19 years with a weighted average remaining useful life of 13.8 years. Amortizable product trade names have useful lives of 10 years with a weighted average remaining useful life of 9.2 years. The Avaya trade name is expected to generate cash flows indefinitely and, consequently, this asset is classified as an indefinite-lived intangible and is therefore not amortized.
Amortization expense for the period from December 16, 2017 through September 30, 2018 (Successor), the period from October 1, 2017 through December 15, 2017 (Predecessor), and fiscal 2017 and 2016 (Predecessor), was $262 million, $13 million, $224 million and $256 million, respectively.
Future amortization expense of intangible assets as of September 30, 2018 for the fiscal years ending September 30, is as follows:
(In millions)
 
2019
$
333

2020
333

2021
332

2022
305

2023 and thereafter
1,594

Total
$
2,897


The Period from December 16, 2017 through September 30, 2018 (Successor) and the Period from October 1, 2017 through December 15, 2017 (Predecessor)
At July 1, 2018, the Company performed its annual impairment test of indefinite-lived intangible assets. The Company determined that the respective carrying amounts of the indefinite-lived intangible assets did not exceed their estimated fair values and therefore no impairment existed.
The Company assessed whether there were any triggering events that would indicate a potential impairment of its finite-lived intangible assets and did not identify any such triggering events or impairment indicators.
Fiscal 2017 (Predecessor)
Prior to the goodwill impairment testing on June 30, 2017, the Company performed an impairment test of indefinite-lived intangible assets and other long-lived assets as of June 30, 2017. The Company estimated the fair values of its indefinite-lived intangible assets using the royalty savings method, which values an asset by estimating the royalties saved through ownership of the asset. As a result of the impairment test, the Company estimated the fair value of its trademarks and trade names to be $190 million as compared to a carrying amount of $255 million and recorded an impairment charge of $65 million.
At July 1, 2017, the Company performed its annual test of impairment of indefinite-lived intangible assets. The Company determined that the respective carrying amounts of the indefinite-lived intangible assets did not exceed their estimated fair values and therefore no impairment existed.
Fiscal 2016 (Predecessor)
Prior to the annual goodwill impairment testing, the Company performed its annual test of impairment of indefinite-lived intangible assets at July 1, 2016. Using the Company forecasts, the Company estimated the fair values of its indefinite-lived intangible assets using the royalty savings method, which values an asset by estimating the royalties saved through ownership of the asset. As a result of the impairment test, the Company estimated the fair value of the indefinite-lived intangible assets to be $255 million as compared to a carrying amount of $355 million and recorded an impairment charge of $100 million related to trademark and trade name indefinite-lived intangible assets.