Avaya (AVYA) 10-K 25 Nov 20 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Oct. 31, 2020	Mar. 31, 2020
Document And Entity Information [Abstract]
Entity Registrant Name	AVAYA HOLDINGS CORP.
Entity Central Index Key	0001418100
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		83,392,096
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 662
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Emerging Growth Company	false
Entity Small Business	false
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-38289
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	2605 Meridian Parkway, Suite 200
Entity Address, State or Province	NC
Entity Address, City or Town	Durham,
Entity Tax Identification Number	26-1119726
Entity Address, Postal Zip Code	27713
City Area Code	908
Local Phone Number	953-6000
Entity Registrant Name	AVAYA HOLDINGS CORP.
Security Exchange Name	NYSE
Trading Symbol	AVYA
Title of 12(b) Security	Common Stock
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Bankruptcy Proceedings, Reporting Current	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		83,392,096
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Public Float			$ 662
ICFR Auditor Attestation Flag	true

Goodwill

Goodwill	12 Months Ended
	Sep. 30, 2020
Goodwill [Line Items]
Schedule of Goodwill	The changes in the carrying amount of goodwill by segment for the periods indicated were as follows: (In millions) Products & Solutions Services Total Balance as of September 30, 2018 (Successor) Cost $ 1,283 $ 1,481 $ 2,764 Accumulated impairment charges — — — 1,283 1,481 2,764 Impairment charges 657 — 657 Foreign currency fluctuations (1) (1) (2) Other — (2) (2) Balance as of September 30, 2019 (Successor) Cost 1,282 1,478 2,760 Accumulated impairment charges (657) — (657) 625 1,478 2,103 Impairment charges (624) — (624) Foreign currency fluctuations (1) 1 — Other — (1) (1) Balance as of September 30, 2020 (Successor) Cost 1,281 1,478 2,759 Accumulated impairment charges (1,281) — (1,281) $ — $ 1,478 $ 1,478

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2017
REVENUE
Total Revenues	$ 604	$ 755	$ 721	$ 682	$ 715	$ 723	$ 717	$ 709	$ 738	$ 2,247	$ 2,873	$ 2,887
COSTS
Cost of Revenue	242									1,104	1,293	1,312
Gross Profit	362	418	397	371	394	392	390	386	407	1,143	1,580	1,575
OPERATING EXPENSES
Selling, general and administrative	264									888	1,013	1,001
Research and development	38									172	207	204
Amortization of intangible assets	10									127	161	162
Impairment charges	0									0	624	659
Restructuring charges, net	14									81	30	22
TOTAL OPERATING EXPENSES	326									1,268	2,035	2,048
OPERATING (LOSS) INCOME	36	74	53	(597)	15	52	(613)	38	50	(125)	(455)	(473)
Interest expense	(14)									(169)	(226)	(237)
Other income (expense), net	(2)									35	63	41
Reorganization items, net	3,416									0	0	0
(LOSS) INCOME BEFORE INCOME TAXES	3,436									(259)	(618)	(669)
(Provision for) benefit from income taxes	(459)	20	(20)	(37)	(25)	(32)	27	6	(3)	546	(62)	(2)
Net (loss) income	$ 2,977	$ 37	$ 9	$ (672)	$ (54)	$ (34)	$ (633)	$ (13)	$ 9	$ 287	$ (680)	$ (671)	$ 2,977
(LOSS) EARNINGS PER SHARE
Net income (loss) per common share - basic (in usd per share)	$ 5.19	$ 0.40	$ 0.08	$ (7.24)	$ (0.54)	$ (0.31)	$ (5.70)	$ (0.12)	$ 0.08	$ 2.61		$ (6.06)
Net income (loss) per common share - diluted (in usd per share)	$ 5.19	$ 0.39	$ 0.08	$ (7.24)	$ (0.54)	$ (0.31)	$ (5.70)	$ (0.12)	$ 0.08	$ 2.58		$ (6.06)
Weighted average shares outstanding
Weighted average number of shares - basic (in shares)	497.3									109.9	92.2	110.8
Weighted average number of shares - diluted (in shares)	497.3									111.1	92.2	110.8
Products
REVENUE
Total Revenues	$ 253									$ 989	$ 1,073	$ 1,222
COSTS
Total Cost of Goods and Services	84									372	405	442
Amortization of technology intangible assets	3									135	174	174
Services
REVENUE
Total Revenues	351									1,258	1,800	1,665
COSTS
Total Cost of Goods and Services	$ 155									$ 597	$ 714	$ 696

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Net (loss) income	$ 2,977	$ 287	$ (680)	$ (671)
Cumulative translation adjustment	3	(31)	(39)	24
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent	(655)	(51)	2	157
Change in interest rate swaps, net of income taxes of $3 for fiscal 2020; $19 for fiscal 2019 and $1 for the period from December 16, 2017 through September 30, 2018	0	(2)	(31)	(58)
Other comprehensive (loss) income	658	18	(72)	(191)
Elimination of Predecessor Company accumulated other comprehensive loss	790	0	0	0
Total comprehensive (loss) income	4,425	305	(752)	(862)
Accumulated Other Comprehensive (Loss) Income
Other comprehensive (loss) income	$ 658	$ 18	$ (72)	$ (191)

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Pension, post-retirement and postemployment benefit-related items, tax	$ (58)	$ (19)	$ 0	$ 29
Change in interest rate swaps, tax	$ 0	$ 1	$ 3	$ 19

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Current assets:
Cash and cash equivalents	$ 727	$ 752
Accounts receivable, net	275	314
Inventory	54	63
Contract with Customer, Asset, Net, Current	296	187
Capitalized Contract Cost, Net, Current	115	114
Other current assets	112	115
TOTAL CURRENT ASSETS	1,579	1,545
Property, plant and equipment, net	268	255
Deferred income taxes, net	31	35
Intangible assets, net	2,556	2,891
Goodwill	1,478	2,103
Operating Lease, Right-of-Use Asset	160	0
Other assets	159	121
TOTAL ASSETS	6,231	6,950
Current liabilities:
Debt maturing within one year	0	29
Accounts payable	242	291
Payroll and benefit obligations	198	116
Contract with Customer, Liability, Current	446	472
Operating Lease, Liability, Current	49	0
Business restructuring reserve, current portion	21	33
Other current liabilities	181	158
TOTAL CURRENT LIABILITIES	1,137	1,099
Non-current liabilities:
Long-term debt	2,886	3,090
Pension obligations	749	759
Other post-retirement obligations	215	200
Deferred income taxes, net	38	72
Contract liabilities, non-current	373	78
Operating Lease, Liability, Noncurrent	129	0
Business restructuring reserve, non-current portion	28	36
Other liabilities	312	316
TOTAL NON-CURRENT LIABILITIES	4,730	4,551
TOTAL LIABILITIES	5,867	5,650
Temporary equity	128	0
STOCKHOLDER'S DEFICIENCY
Common stock	1	1
Additional paid-in capital	1,449	1,761
Accumulated deficit	(969)	(289)
Accumulated other comprehensive loss	(245)	(173)
TOTAL STOCKHOLDER'S DEFICIENCY	236	1,300
TOTAL LIABILITIES AND STOCKHOLDER'S DEFICIENCY	$ 6,231	$ 6,950

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Oct. 31, 2019	Sep. 30, 2019	Dec. 15, 2017
Common stock, par value (usd per share)	$ 0.01		$ 0.01
Common stock, shares authorized	550,000,000		550,000,000
Common stock, shares issued	83,278,383		111,046,085	110,000,000
Common stock, shares outstanding	83,278,383		111,033,405
Preferred Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01
Preferred stock, shares authorized	55,000,000		55,000,000
Preferred Stock, Shares Issued	125,000
Preferred Stock, Shares Outstanding		125,000	0
Series A Preferred Stock
Preferred Stock, Par or Stated Value Per Share	$ 1,000
Preferred Stock, Shares Issued	125,000		0
Preferred Stock, Shares Outstanding	125,000		0

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($) $ in Millions	Total	Parent Company	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income
Beginning Balance (in shares) at Sep. 30, 2017			494,800,000
Beginning Balance at Sep. 30, 2017	$ (5,013)		$ 0	$ 2,389	$ (5,954)	$ (1,448)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	2,977	$ 2,977
Other comprehensive income (loss)	658					658
Cancellation of Predecessor equity (in shares)			(494,800,000)
Cancellation of Predecessor equity	1,380			(2,387)	2,977	790
Ending Balance at Dec. 15, 2017	1,668		$ 1	1,667	0	0
Ending Balance (in shares) at Dec. 15, 2017			110,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cancellation of Predecessor Equity, Par Value			$ 0
Stockholder's Equity Attributable to Parent, Prior to Cancellation of Predecessor Equity			$ 0
Balance as of December 15, 2017 (Predecessor) (in shares)			494,800,000
Stockholders' Equity, Including Portion Attributable To Noncontrolling Interest, Prior To Cancellation Of Predecessor Equity	(1,380)			2,387	(2,977)	(790)
Common stock issued for Predecessor debt (in shares)			103,900,000
Common stock issued for Predecessor debt	1,576		$ 1	1,575
Common stock issued for Pension Benefit Guaranty Corporation (in shares)			6,100,000
Common stock issued for Pension Benefit Guaranty Corporation	92			92
Reorganization, Stock Issued for Employee Benefit Plans, Value	0
Issuance of common stock, net of shares redeemed and canceled, under employee stock option plan (in shares)			200,000
Share-based compensation expense	0			0
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	2			2
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	19			19
Net (loss) income	287	287			287
Other comprehensive income (loss)	18					18
Shares repurchased and retired for tax withholding on vesting of restricted stock units	67			67
Purchase of convertible note bond hedge, net of income taxes	(64)			(64)
Issuance of call spread warrants	58			58
Ending Balance at Sep. 30, 2018	2,051		$ 1	1,745	287	18
Ending Balance (in shares) at Sep. 30, 2018			110,200,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of shares redeemed and canceled, under employee stock option plan (in shares)			1,300,000
Share-based compensation expense	0			0
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation			(500,000)
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	9			9
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	25			25
Net (loss) income	(671)	(671)			(671)
Other comprehensive income (loss)	(191)					(191)
Ending Balance at Sep. 30, 2019	1,300	1,300	$ 1	1,761	(289)	(173)
Ending Balance (in shares) at Sep. 30, 2019			111,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of shares redeemed and canceled, under employee stock option plan (in shares)			1,500,000
Share-based compensation expense	0
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation			(500,000)
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	7			7
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	30			30
Preferred stock, accretion of discount	(4)			(4)
Dividends, Preferred Stock	(3)			(3)
Net (loss) income	(680)	(680)			(680)
Stock Issued During Period, Value, Employee Stock Purchase Plan	2			2
Stock Issued During Period, Shares, Employee Stock Purchase Plans			200,000
Other comprehensive income (loss)	(72)					(72)
Stock Repurchased and Retired During Period, Value	(330)			(330)
Ending Balance at Sep. 30, 2020	$ 236	$ 236	$ 1	$ 1,449	$ (969)	$ (245)
Ending Balance (in shares) at Sep. 30, 2020			83,300,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Repurchased During Period, Shares	(28,923,664)
Stock Repurchased and Retired During Period, Shares			28,900,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 435	$ 704	$ 731	$ 756
OPERATING ACTIVITIES:
Net (loss) income	2,977	287	(680)	(671)
Adjustments to reconcile loss from continuing operations to net cash provided by operating activities:
Depreciation and amortization	31	384	423	443
Share-based compensation	0	19	30	25
Amortization of debt issuance costs and discounts	0	8	23	22
Gain (Loss) on Extinguishment of Debt	0	0	7	0
Deferred income taxes, net	455	(588)	(29)	(54)
Asset Impairment Charges	0	0	624	659
Change in fair value of emergence date warrants	0	17	3	(29)
Unrealized loss (gain) on foreign currency transactions	0	(36)	24	9
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	0	0	10	0
Marketable Securities, Realized Gain (Loss)	0	0	(59)	0
Other non-cash (credits) charges, net	0	(3)	(9)	(7)
Reorganization items:
Net gain on settlement of Liabilities subject to compromise	(1,778)	0	0	0
Payment to PBGC	(340)	0	0	0
Payment to pension trust	(49)	0	0	0
Payment of unsecured claims	(58)	0	0	0
Fresh start adjustments, net	(1,697)	0	0	0
Non-cash and financing related reorganization items, net	26	0	0	0
Changes in operating assets and liabilities:
Accounts receivable	40	13	37	58
Inventory	0	36	8	(7)
Increase (Decrease) in Operating Lease Right-of-Use Assets and Liabilities	0	0	13	0
Increase (Decrease) in Contract with Customer, Asset	0	0	(166)	(122)
Increase (Decrease) In Capitalized Contract Costs, Net	0	0	5	(13)
Accounts payable	(40)	(16)	(48)	24
Payroll and benefit obligations	16	(71)	46	(73)
Increase (Decrease) in Restructuring Reserve	(7)	29	(19)	(25)
Increase (Decrease) in Contract with Customer, Liability	28	160	(71)	35
Other assets and liabilities	(18)	(43)	(25)	(47)
Net cash used for operating activities	(414)	202	147	241
INVESTING ACTIVITIES:
Capital expenditures	(13)	(61)	(98)	(113)
Acquisition of businesses, net of cash acquired	0	(157)	0	0
Amortization of debt issuance costs	0	0	0	(10)
Proceeds from Sale and Maturity of Marketable Securities	0	0	412	0
Proceeds from sale-leaseback transactions	0	17	0	0
Other investing activities, net	0	2	0	(1)
Net cash used for investing activities	(13)	(199)	314	(124)
FINANCING ACTIVITIES:
Payments for Repurchase of Common Stock	0	0	(330)	0
Proceeds from Issuance of Preferred Stock and Preference Stock	0	0	121	0
Repayments of Other Long-term Debt	111	22	1,231	29
Repayments of Short-term Debt	(725)	0	0	0
Proceeds from issuance of senior notes	(2,061)	0	0	0
Purchase of convertible note bond hedge	0	58	0	0
Payments for Hedge, Financing Activities	0	(84)	0	0
Payments of Debt Issuance Costs	(97)	(10)	(14)	0
Payment for Contingent Consideration Liability, Financing Activities	0	0	(5)	(9)
Finance Lease, Principal Payments	(4)	(10)	(10)	(14)
Proceeds from Stock Plans	0	0	3	0
Other financing activities, net	0	(2)	(7)	(9)
NET CASH USED FOR FINANCING ACTIVITIES	(102)	273	(489)	(61)
Effect of exchange rate changes on cash and cash equivalents	(2)	(7)	3	(4)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(531)	269	(25)	52
Term Loan Credit Agreement due December 15, 2024
FINANCING ACTIVITIES:
Proceeds from long term debt	2,896	0	0	0
Term Loan Credit Agreement Due To Refinancing
FINANCING ACTIVITIES:
Proceeds from long term debt	0	2,911	1,627	0
Repayment of long-term debt	0	(2,918)	(1,643)	0
Convertible Notes
FINANCING ACTIVITIES:
Proceeds from long term debt	0	350	0	0
Senior Notes
FINANCING ACTIVITIES:
Proceeds from long term debt	$ 0	$ 0	$ 1,000	$ 0

Background and Basis of Present

Background and Basis of Presentation	12 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	Background and Basis of Presentation Background Avaya Holdings Corp. (the "Parent" or "Avaya Holdings"), together with its consolidated subsidiaries (collectively, the "Company" or "Avaya"), is a global leader in digital communications products, solutions and services for businesses of all sizes delivering most of its technology through software and services. Avaya builds open, converged and innovative solutions to enhance and simplify communications and collaboration in the cloud, on-premise or a hybrid of both. The Company's global team of professionals delivers services from initial planning and design, to implementation and integration, to ongoing managed operations, optimization, training and support. The Company manages its business operations in two segments, Products & Solutions and Services. The Company sells directly to customers through its worldwide sales force and indirectly through its global network of channel partners, including distributors, service providers, dealers, value-added resellers, system integrators and business partners that provide sales and services support. Basis of Presentation Avaya Holdings has no material assets or standalone operations other than its ownership of direct wholly-owned subsidiary Avaya Inc. and its subsidiaries. The accompanying Consolidated Financial Statements reflect the operating results of Avaya Holdings and its consolidated subsidiaries and have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and the rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). On January 19, 2017 (the "Petition Date"), Avaya Holdings, together with certain of its affiliates, namely Avaya CALA Inc., Avaya EMEA Ltd., Avaya Federal Solutions, Inc., Avaya Holdings LLC, Avaya Holdings Two, LLC, Avaya Inc., Avaya Integrated Cabinet Solutions Inc. (n/k/a Avaya Integrated Cabinet Solutions LLC), Avaya Management Services Inc., Avaya Services Inc., Avaya World Services Inc., Octel Communications LLC, Sierra Asia Pacific Inc., Sierra Communication International LLC, Technology Corporation of America, Inc., Ubiquity Software Corporation, VPNet Technologies, Inc. and Zang, Inc. (n/k/a Avaya Cloud Inc.) (the "Debtors"), filed voluntary petitions for relief (the "Bankruptcy Filing") under Chapter 11 of the United States Bankruptcy Code (the "Bankruptcy Code") in the United States Bankruptcy Court for the Southern District of New York (the "Bankruptcy Court"). The cases were jointly administered as Case No. 17-10089 (SMB). The Bankruptcy Court confirmed the Second Amended Joint Chapter 11 Plan of Reorganization of Avaya Inc. and its Debtor Affiliates filed on October 24, 2017 (the "Plan of Reorganization") on November 28, 2017. Confirmation of the Plan of Reorganization resulted in the discharge of certain claims against the Company that arose before the Petition Date and terminated all rights and interests of the pre-filing equity security holders as provided for in the Plan of Reorganization and as further discussed in Note 23, "Emergence from Voluntary Reorganization under Chapter 11 Proceedings." The Debtors operated their businesses as "debtors-in-possession" under the jurisdiction of the Bankruptcy Court and in accordance with the applicable provisions of Chapter 11 of the Bankruptcy Code and the orders of the Bankruptcy Court until the Plan of Reorganization was substantially consummated and they emerged from bankruptcy on December 15, 2017 (the "Emergence Date"). On the Emergence Date, the Company applied fresh start accounting, which resulted in a new basis of accounting and the Company becoming a new entity for financial reporting purposes. As a result of the application of fresh start accounting and the effects of the implementation of the Plan of Reorganization, the Consolidated Financial Statements after the Emergence Date are not comparable with the Consolidated Financial Statements on or before that date. See Note 24, "Fresh Start Accounting," for additional information. References to "Successor" or "Successor Company" refer to the financial position and results of operations of the reorganized Avaya Holdings after the Emergence Date. References to "Predecessor" or "Predecessor Company" refer to the financial position and results of operations of Avaya Holdings on or before the Emergence Date. During the second quarter of fiscal 2020, the World Health Organization characterized a novel strain of coronavirus ("COVID-19") as a pandemic. The spread of COVID-19 around the globe and the actions required to mitigate its impact have created substantial disruption to the global economy. The duration of the pandemic and the long-term impacts on the global economy are uncertain. Although the COVID-19 pandemic did not have a material impact on the Company’s revenue and gross margin during fiscal 2020, the Company did recognize a significant goodwill impairment charge during fiscal 2020 as a result of the COVID-19 pandemic. See Note 7, “Goodwill, net” for additional information regarding the goodwill impairment charge recorded during fiscal 2020. The accompanying Consolidated Financial Statements of the Company have been prepared assuming that the Company will continue as a going concern and contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. While we believe existing cash and cash equivalents of $727 million as of September 30, 2020, future cash provided by operating activities and borrowings available under the ABL Credit Agreement will be sufficient to

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Accounting Policy Changes The Company emerged from bankruptcy on December 15, 2017 and qualified for fresh start accounting. Fresh start accounting allows a company to set new accounting policies for the successor company independent of those followed by the predecessor company. As such, the Successor Company adopted certain accounting policy changes, which have been detailed in the "Share-based Compensation" and "Foreign Currency Translation" accounting policies below. Use of Estimates Management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and revenue and expenses during the periods reported. Estimates and assumptions are reviewed periodically, and the effects of revisions are reflected in the Consolidated Financial Statements in the period they are determined to be necessary. Actual results could differ from these estimates. The spread of COVID-19 and the actions required to mitigate its impact have created substantial disruption to the global economy. The duration of the pandemic and the long-term impacts on the global economy are uncertain. The pandemic may affect management's estimates and assumptions, in particular those that require a projection of our financial results, our cash flows or broader economic conditions, such as the collectability of accounts receivable, sales returns and allowances, the use and recoverability of inventory, the realization of deferred tax assets, annual effective tax rate, the fair value of equity compensation, the recoverability of long-lived assets, useful lives and impairment of tangible and intangible assets including goodwill (see Note 7, "Goodwill, net"), business restructuring reserves, and fair value measurements (see Note 13, "Fair Value Measurements"). The Company also uses estimates to assess pension and post-retirement benefit costs, the fair value of assets and liabilities in connection with fresh start accounting and those acquired in business combinations, and the amount of exposure from potential loss contingencies, among others. Principles of Consolidation The Consolidated Financial Statements include the accounts of Avaya Holdings Corp. and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the current year's presentation. Revenue Recognition The Company derives revenue primarily from the sale of products and services for communications systems and applications. The Company sells directly through its worldwide sales force and indirectly through its global network of channel partners, including distributors, service providers, dealers, value-added resellers, systems integrators and business partners that provide sales and services support. On October 1, 2018, the Company adopted Accounting Standards Update ("ASU") No. 2014-09, "Revenue from Contracts with Customers (Topic 606)" ("ASC 606"). This standard superseded most of the previous revenue recognition guidance under GAAP and is intended to improve and converge with international standards the financial reporting requirements for revenue recognition. The Company adopted ASC 606 using the modified retrospective transition method applied to all open contracts with customers that were not completed as of September 30, 2018. On October 1, 2018, the Company recorded a net increase to the opening Retained earnings balance of $95 million, net of tax, due to the cumulative impact of adopting ASC 606. Under the modified retrospective method, results for reporting periods beginning after September 30, 2018 are presented under ASC 606 while prior period financial information is not adjusted and continues to be reported under prior guidance (“ASC 605”). In accordance with ASC 606, the Company accounts for a customer contract when both parties have approved the contract and are committed to perform their respective obligations, each party’s rights can be identified, payment terms can be identified, the contract has commercial substance and it is at least probable that the Company will collect the consideration to which it is entitled. The Company accrues a provision for estimated sales returns and other allowances, including promotional marketing programs and other incentives, as a reduction of revenue at the time of sale. When estimating returns, the Company considers customary inventory levels held by third-party distributors. Revenue is recognized upon the transfer of control of the promised products and services to customers. Judgment is required in instances where the Company’s contracts include multiple products and services to determine whether each should be accounted for as a separate performance obligation. The Company enters into contracts that include various combinations of products and services, each of which is generally capable of being distinct as well as distinct within the context of the contracts. Customer contracts are typically made pursuant to purchase orders and statements of work based on master purchase or partner agreements. Invoicing typically occurs upon customer acceptance or monthly for a series of services. Payment is due based on the Company’s standard payment terms which are typically within 30 to 60 days of invoice issuance. The Company does not typically provide financing arrangements to customers. For certain services and customer types, customers will remit payment before the services are provided. In instances where the timing of revenue recognition differs from the timing of invoicing, the Company determined that contracts do not include a significant financing component. The primary purpose of the invoicing terms is to provide customers with simplified and predictable ways of purchasing products and services, not to receive financing from or to provide financing to customers. Certain contracts include performance obligations accounted for as a series which also include variable consideration (primarily usage-based fees). For these arrangements, variable consideration is not estimated and allocated to the entire performance obligation, rather the variable fees are recognized in the period in which the usage occurs in accordance with the "right to invoice" practical expedient. The total transaction price for each contract is determined based on the total consideration specified in the contract, including variable consideration such as sales incentives and other discounts. The expected value method is generally used when estimating variable consideration, which typically reduces the total transaction price due to the nature of the elements to which the variable consideration relates. These estimates reflect the Company’s historical experience, current contractual requirements, specific known market events and trends, industry data and forecasted customer buying patterns. The Company excludes from the transaction price all taxes assessed by governmental authorities that are both (i) imposed on and concurrent with a specific revenue-producing transaction and (ii) collected from customers. Accordingly, such tax amounts are not included as a component of net sales or cost of sales. The expected value method requires judgment and considers multiple factors that may vary over time depending upon the unique facts and circumstances related to each performance obligation. Depending on the facts and circumstances, a change in variable consideration estimate will either be accounted for at the contract level or using the portfolio method. Reserves for contractual stock rotation rights to channel partners to support the management of inventory and certain other sales incentives are determined using the portfolio method. The Company also considers the customers’ rights of return in determining the transaction price where applicable. The Company allocates the transaction price to each performance obligation based on its relative standalone selling price and recognizes revenue as each performance obligation is satisfied. Judgment is required to determine the standalone selling price for each distinct performance obligation. The Company uses a range of selling prices to estimate standalone selling price when each of the products and services is sold separately. The Company typically has more than one standalone selling price for individual products and services due to the stratification of those products and services by customers and circumstances. In these instances, the Company may use information such as the size of the customer and geographic region in determining the standalone selling price. In instances where standalone selling price is not directly observable, such as when the Company does not sell the product or service separately, the Company determines the standalone selling price using information that may include market conditions and other observable inputs. Amounts billed to customers for shipping and handling activities are considered contract fulfillment activities and not a separate performance obligation of the contract. Shipping and handling fees are recorded as revenue and the related cost is a cost to fulfill the contract. Contract modifications are accounted for as separate contracts if the additional products and services are distinct and priced at standalone selling prices. If the additional products and services are distinct, but not priced at standalone selling prices, the modification is treated as a termination of the existing contract and the creation of a new contract. Lastly, if the additional products and services are not distinct within the context of the contract, the modification is combined with the original contract and either an increase or decrease in revenue is recognized on the modification date. The Company records a contract asset when revenue is recognized in advance of the right to bill, pursuant to customer contract terms. The contract asset decreases when the Company has the right to bill the customer which is generally triggered by the satisfaction of additional performance obligations or contract milestones. The Company records a contract liability when payment is received from the customer in advance of the Company satisfying a performance obligation and the contract liability is reduced as performance obligations are satisfied and revenue is recognized. The Company records the net contract asset or liability position for each customer contract. Software The Company’s software licenses provide users with access to capabilities such as voice, video, conferencing, messaging and collaboration. The Company’s software licenses also add functionality to the Company’s hardware. The Company’s software licenses for on-premise customer software provide the customer with a right to use the software as it exists when it is made available to the customer and are accounted for as distinct performance obligations. The Company’s software licenses are sold through both direct and indirect channels with terms that are either perpetual or time based, both of which provide the end-user with the same functionality. The main difference between perpetual and term licenses is the duration over which the customer benefits from the software. Revenue from on-premise customer software licenses is generally recognized at the point-in-time the software is made available to the customer, via direct sale to the end-user or indirect sale to a channel partner, based on the fixed minimum revenue commitment under the arrangement. However, revenue is not recognized before the beginning of the period during which the customer can use and benefit from the license. In instances where the Company’s software licenses include a usage-based fee, revenue associated with the incremental usage is recognized at the point-in-time the incremental usage occurs. The Company also sells its software under its subscription-based offerings which mainly consist of term software license arrangements and software as a service ("SaaS") arrangements. Term software licenses include multiple performance obligations where the term licenses are recognized at the point-in-time of transfer of control of the software, with the associated software maintenance revenue recognized ratably over the contract term as the customer consumes the services. SaaS arrangements do not include the right for the customer to take possession of the software during the contractual term of the arrangement, and therefore have one distinct performance obligation which is satisfied over time with revenue recognized ratably over the contract term as the customer consumes the services. Subscription-based offerings typically have terms that range from one to five years. ACO Avaya Cloud Office by RingCentral or “ACO”, was introduced by the Company to accelerate the Company's transition to the cloud. Through this partnership, ACO combines RingCentral's UCaaS platform with Avaya technology, services and migration capabilities to create a differentiated UCaaS offering. These services are accounted for as two distinct performance obligations, one being a licensing component that is generally recognized at the point-in-time the software is made available to the customer, and the second being associated support services which represents a stand-ready obligation whereby the revenues are generally recognized ratably over the contract term. The Company’s ACO solution is provided through both direct and indirect channels. Contracts typically have terms that range from one to five years. Hardware The Company’s hardware, phones, gateways, and servers, each of which has a stand-alone functionality, are generally considered distinct performance obligations. Hardware is sold through both direct and indirect channels and revenue is recognized at the point-in-time at which control of the product is transferred to the customer, via direct sale to the end-user or indirect sale to a channel partner, generally upon delivery, as defined in the contract. Global Support Services The Company’s global support services provide supplemental maintenance options to end-users in support of the Company’s products and solutions, including when and if available upgrade rights and maintenance for hardware. These services are typically accounted for as distinct performance obligations. Given that global support services consist of a series of distinct promises that are satisfied over time in the form of a single performance obligation comprised of a stand-ready obligation, these services are generally recognized ratably over the period during which the services are performed as customers simultaneously consume and receive benefits. Maintenance contracts typically have terms that range from one to five years. Professional Services The Company’s professional services include the design, implementation and development of communication solutions. Professional services are sold through the Company’s direct and indirect channels either on a stand-alone basis or with other hardware, software and services and are generally accounted for as distinct performance obligations. Revenue for professional services is generally recognized over time based on the cost of effort incurred to date relative to the total cost of effort expected to be incurred as customers simultaneously consume and receive benefits. Effort incurred generally represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Contracts for professional services typically have terms that range from four to six weeks for simple engagements and from six months to three years for more complex engagements. Prior to the adoption of ASC 606, revenue for professional services was recognized upon completion and acceptance of the project and when such arrangements included products, product revenue was also recognized upon completion and acceptance of the project. Cloud and Managed Services The Company’s managed services provide additional support options to end-users on top of the Company’s supplemental maintenance services, including hardware support, help-desk routing and system monitoring services. The Company’s managed services are sold either on a stand-alone basis or together with the Company’s hardware, software and other services, and are generally accounted for as distinct performance obligations. The Company’s managed services are provided through both direct and indirect channels. Managed services consist of a series of distinct promises that are satisfied over time in the form of a single performance obligation comprised of a stand-ready obligation. Contracts for managed services typically have terms that range from one to five years. The Company’s cloud offerings enable customers to take advantage of its technology via the cloud, or as a hybrid with its on-premise solutions. The software that enables the core communications functionality is offered both as a sale of perpetual or time based licenses or through a SaaS arrangement. Cloud offerings can include supplemental maintenance and managed services and are sold through the Company’s direct and indirect channels. Cloud and managed services offerings often include multiple performance obligations. Each performance obligation can itself include a series of distinct promises that are satisfied over time. Total consideration for a project is allocated to each performance obligation, with revenue recognized ratably over the period during which the services are performed as customers simultaneously consume and receive benefits. Variable consideration from incremental usage above a fixed fee is recognized at the point-in-time at which the usage occurs. Warranties The Company offers standard limited warranties that provide the customer with assurance that its products will function in accordance with contract specifications. The Company’s standard limited warranties are not sold separately but are included with each customer purchase. Warranties are not considered separate performance obligations, and therefore, warranty expense is accrued at the time the related revenue is recognized. Cash and Cash Equivalents All highly liquid investments with original maturities of three months or less at the date of purchase are classified as cash equivalents. Concentrations of Risk The Company’s cash and cash equivalents are maintained with several financial institutions. Deposits held at banks may exceed the amount of insurance provided on such deposits. Generally, these deposits may be redeemed upon demand and are maintained with financial institutions with reputable credit and therefore bear minimal credit risk. The Company seeks to mitigate such risks by spreading its risk across multiple counterparties and monitoring the risk profiles of these counterparties. The Company, from time to time, may enter into derivative financial instruments with high credit quality financial institutions to manage foreign exchange rate and interest rate risk and is exposed to losses in the event of non-performance by the counterparties to these contracts. To date, no counterparty has failed to meet its obligations to the Company. The Company relies on a limited number of contract manufacturers and suppliers to provide manufacturing services for its products. The inability of a contract manufacturer or supplier to fulfill supply requirements of the Company could materially impact future operating results. The Company's largest distributor is also its largest customer and represented 8% of the Company's total annual consolidated revenue for fiscal 2020. Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded when the customer has been billed or the right to consideration is unconditional. Accounts receivable are recorded net of reserves for sales returns and allowances and provisions for doubtful accounts. The Company performs ongoing credit evaluations of its customers and generally does not require collateral from its customers. The allowances are based on analyses of historical trends, aging of accounts receivable balances and the creditworthiness of customers as determined by credit checks, analyses and payment history. At September 30, 2020 and 2019, one distributor accounted for approximately 9% and 12% of accounts receivable. Inventory Inventory includes goods awaiting sale (finished goods) and goods to be used in connection with providing maintenance services. Inventory is stated at the lower of cost or net realizable value, determined on a first-in, first-out method. Reserves to reduce the inventory cost to net realizable value are based on current inventory levels, assumptions about future demand and product life cycles for the various inventory types. The Company has outsourced the manufacturing of substantially all of its products and may be obligated to purchase certain excess inventory levels from its outsourced manufacturers if actual sales of product are lower than forecast, in which case additional inventory provisions may need to be recorded in the future. Contract Assets The Company recognizes a contract asset when it transfers products and services to a customer in advance of scheduled billings. Contract assets decrease when the Company invoices the customer or the right to receive consideration is unconditional. Contract Costs The Company capitalizes direct and incremental costs incurred to obtain and to fulfill a contract in advance of revenue recognition, such as sales commissions, business partner incentives and certain labor, third party service and related product costs. These costs are recognized as an asset if the Company expects to recover them. Costs to obtain a contract are amortized using the portfolio approach over the average term of the customer contracts, which corresponds to the period of benefit. Costs incurred to obtain a contract with an amortization period of one year or less are expensed as incurred in accordance with the prescribed practical expedient. Contract fulfillment costs are recognized consistent with the transfer to the customer of the underlying performance obligations based on the specific contracts to which they relate. Research and Development Costs Research and development costs are charged to expense as incurred. The costs incurred for the development of communications software that will be sold, leased or otherwise marketed, however, are capitalized when technological feasibility has been established in accordance with FASB ASC Topic 985, "Software" ("ASC 985"). The Company has continued to leverage agile development methodologies, which are characterized by a more dynamic development process with more frequent revisions to a product releases' features and functions as the software is being developed with technological feasibility being met shortly before the product revision is made generally available. As such, no amounts were capitalized for internally developed software costs in the Company's Consolidated Financial Statements during fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor). Property, Plant and Equipment Property, plant and equipment are stated at cost less accumulated depreciation. Depreciation is determined using the straight-line method over the estimated useful lives of the assets. Estimated lives range from 2 to 10 years for machinery and equipment and the remaining lease term for equipment acquired under a financing lease. Improvements that extend the useful life of assets are capitalized and maintenance and repairs are charged to expense as incurred. Capitalized improvements to facilities subject to operating leases are depreciated over the lesser of the estimated useful life of the asset or the duration of the lease. Upon retirement or disposal of assets, the cost and related accumulated depreciation are removed from the Consolidated Balance Sheets and any gain or loss is reflected in the Consolidated Statements of Operations. The Company capitalizes costs associated with software developed or obtained for internal use when the preliminary project stage is completed and it is determined that the software will provide enhanced capabilities. Internal use software is amortized on a straight-line basis generally over 5 to 7 years. Costs capitalized include payroll and related benefits, third party development fees and acquired software and licenses. General and administrative costs, overhead, maintenance and training, and the cost of the software that does not add functionality to existing systems, are expensed as incurred. The Company had unamortized internal use software costs included in Property, Plant and Equipment, net in the Consolidated Balance Sheets of $91 million and $83 million as of September 30, 2020 and 2019, respectively. Depreciation expense related to internal use software recognized in the Consolidated Statements of Operations for fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor) was $27 million, $39 million, $31 million and $5 million, respectively. Acquisition Accounting The Company accounts for business combinations using the acquisition method, which requires an allocation of the purchase price of an acquired entity to the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. Goodwill represents the excess of the purchase price over the net tangible and intangible assets acquired. Goodwill Goodwill is not amortized but is subject to periodic testing for impairment in accordance with FASB ASC Topic 350, "Intangibles-Goodwill and Other" ("ASC 350") at the reporting unit level. The Company's reporting units are subject to impairment testing annually, on July 1 st , or more frequently if events occur or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. The Company's goodwill was primarily recorded upon emergence from bankruptcy as a result of applying fresh start accounting. ASC 350 provides the option to assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. The Company has the unconditional option to bypass the qualitative assessment for any reporting unit in any period and proceed directly to performing a quantitative goodwill impairment test. If the assessment of all relevant qualitative factors indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, a quantitative goodwill impairment test is not necessary. If the assessment of all relevant qualitative factors indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the Company will perform a quantitative goodwill impairment test. The quantitative impairment test for goodwill consists of a comparison of the fair value of a reporting unit with its carrying value, including the goodwill allocated to that reporting unit. If the carrying value of a reporting unit exceeds its fair value, the Company will recognize an impairment loss equal to the amount of the excess, limited to the amount of goodwill allocated to that reporting unit. Application of the impairment test requires judgement, including the identification of reporting units, assignment of assets and liabilities to reporting units and the determination of fair value of each reporting unit. In performing the quantitative goodwill impairment test, the Company estimates the fair value of each reporting unit using a weighting of fair values derived from an income approach and a market approach. Under the income approach, the fair value of a reporting unit is estimated using a discounted cash flows model. Future cash flows are based on forward-looking information regarding revenue and costs for each reporting unit and are discounted using an appropriate discount rate. The discounted cash flows model relies on assumptions regarding revenue growth rates, projected gross profit, working capital needs, selling, general and administrative expenses, research and development expenses, business restructuring costs, capital expenditures, income tax rates, discount rates and terminal growth rates. The discount rates the Company uses represent the estimated weighted average cost of capital, which reflects the overall level of inherent risk involved in its reporting unit operations and the rate of return an outside investor would expect to earn. To estimate cash flows beyond the final year of its model, the Company uses a terminal value approach. Under this approach, the Company applies a perpetuity growth assumption to determine the terminal value. The Company incorporates the present value of the resulting terminal value into its estimate of fair value. Forecasted cash flows for each reporting unit consider current economic conditions and trends, estimated future operating results, the Company's view of growth rates and anticipated future economic conditions. Revenue growth rates inherent in the forecasts are based on input from internal and external market intelligence research sources that compare factors such as growth in global economies, regional trends in the telecommunications industry and product evolution. Macroeconomic factors such as changes in economies, product evolution, industry consolidation and other changes beyond the Company's control could have a positive or negative impact on achieving its targets. The market approach estimates the fair value of a reporting unit by applying multiples of operating performance measures to the reporting unit's operating performance (the "Guideline Public Company Method"). These multiples are derived from comparable publicly-traded companies with similar investment characteristics to the reporting unit. The key estimates and assumptions that are used to determine the fair value under the market approach include current and projected 12-month operating performance results, as applicable, and the selection of the relevant multiples that are applied. Intangible and Long-lived Assets Intangible assets include technology and patents, customer relationships and trademarks and trade names. Intangible assets with finite lives are amortized using the straight-line method over the estimated economic lives of the assets, which range from 1 to 19 years. Long-lived assets, including intangible assets with finite lives, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable in accordance with FASB ASC Topic 360, "Property, Plant, and Equipment." Intangible assets determined to have indefinite useful lives are not amortized but are tested for impairment annually, on July 1st, or more frequently if events occur or circumstances change that indicate an asset may be impaired. The recoverability test of finite-lived assets is based on forecasts of undiscounted cash flows for each asset group. The impairment test of the Company’s indefinite-lived intangible asset, the Avaya Trade Name consists of a comparison of the estimated fair value of the asset with its carrying value. If the carrying value of the Avaya Trade Name exceeds its estimated fair value, the Company will recognize an impairment loss equal to the amount of the excess. The fair value of the Avaya Trade Name is estimated using the relief-from-royalty model, a form of the income approach. Under this methodology, the fair value of the trade name is estimated by applying a royalty rate to forecasted net revenues which is then discounted using a risk-adjusted rate of return on capital. Revenue growth rates inherent in the forecast are based on input from internal and external market intelligence research sources that compare factors such as growth in global economies, regional trends in the telecommunications industry and product evolution. The royalty rate is determined using a set of observed market royalty rates. The estimated useful lives of intangible and long-lived assets are based on many factors including assumptions regarding the effects of obsolescence, demand, competition and other economic factors, expectations regarding the future use of the ass
Accounting Changes	Accounting Policy Changes The Company emerged from bankruptcy on December 15, 2017 and qualified for fresh start accounting. Fresh start accounting allows a company to set new accounting policies for the successor company independent of those followed by the predecessor company. As such, the Successor Company adopted certain accounting policy changes, which have been detailed in the "Share-based Compensation" and "Foreign Currency Translation" accounting policies below.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Sep. 30, 2020
Accounting Changes and Error Corrections [Abstract]
Accounting Standards Update and Change in Accounting Principle	Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income." This standard allows companies to reclassify from accumulated other comprehensive income to retained earnings any stranded tax benefits resulting from the enactment of the Tax Cuts and Jobs Act. The Company adopted this standard as of October 1, 2019. The adoption of this standard did not have a material impact on the Company's Consolidated Financial Statements. In February 2016, the FASB issued ASC 842, which superseded all lease accounting guidance and requires lessees to recognize lease assets and liabilities for all leases with initial lease terms of more than 12 months. The standard makes similar changes to lessor accounting and aligns key aspects of the lessor accounting model with the GAAP revenue recognition standard. The Company adopted ASC 842 on October 1, 2019 using the modified retrospective transition method as of the beginning of the period of adoption. Therefore, on October 1, 2019, the Company recognized and measured leases without revising the historical comparative period information or disclosures. The modified retrospective transition method included optional practical expedients which lessened the burden of implementing ASC 842 by not requiring a reassessment of certain conclusions reached under the previous lease accounting guidance. The Company elected to apply the package of practical expedients to forego a reassessment of (1) whether any expired or existing contracts are or contain leases; (2) the lease classification for any expired or existing leases; and (3) the initial direct costs for an existing lease. In addition, the Company elected the land easement practical expedient permitting it to not reassess whether an existing or expired land easement is a lease or contains a lease. The Company also adopted the practical expedient permitting the non-lease components of an arrangement to be included in the right-of-use asset to which they relate. The Company did not elect the practical expedient allowing the use-of-hindsight which would require the Company to reassess the lease term of existing leases based on all facts and circumstances through the effective date. The adoption of ASC 842 had a material impact to the Company's Consolidated Balance Sheet mainly due to the recognition of $190 million of operating lease right-of-use assets and $194 million of operating lease liabilities. The adoption of ASC 842 also resulted in the one-time reclassification of certain prepaid and deferred rent and facility-related business restructuring liabilities to operating lease right-of-use assets. The impact of the adoption of ASC 842 on the September 30, 2019 Consolidated Balance Sheet was as follows: September 30, 2019 Upon Adoption of ASC 842 (In millions) As Reported Adjustments ASSETS Other current assets $ 115 $ (2) $ 113 Intangible assets, net 2,891 (2) 2,889 Operating lease right-of-use assets — 190 190 LIABILITIES Current liabilities: Operating lease liabilities — 51 51 Business restructuring reserve 33 (4) 29 Non-current liabilities: Operating lease liabilities — 143 143 Business restructuring reserve 36 (1) 35 Other liabilities 316 (3) 313 Recent Standards Not Yet Effective In August 2020, the FASB issued ASU No. 2020-06, "Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity." This standard simplifies the accounting for convertible instruments and the application of the derivatives scope exception for contracts in an entity's own equity. The standard also amends the accounting for convertible instruments in the diluted earnings per share calculation and requires enhanced disclosures of convertible instruments and contracts in an entity's own equity. This standard is effective for the Company in the first quarter of fiscal 2023 with early adoption permitted in the first quarter of fiscal 2022. The adoption may be applied on a modified or fully retrospective basis. An entity may also irrevocably elect the fair value option in accordance with Accounting Standards Codification ("ASC") 825 for any financial instrument that is a convertible security upon adoption of this standard. The Company is currently assessing the impact the new guidance will have on its Consolidated Financial Statements. In December 2019, the FASB issued ASU No. 2019-12, "Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes". This standard simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC 740. The amendments also improve consistent application of and simplify GAAP for other areas of ASC 740 by clarifying and amending existing guidance. This standard is effective for the Company beginning in the first quarter of fiscal 2022, with early adoption permitted. Depending on the amendment, adoption may be applied on a retrospective, modified retrospective or prospective basis. The Company intends to early adopt this standard in the first quarter of fiscal 2021 and does not expect the adoption of the standard to have a material impact on its Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-15, "Intangibles - Goodwill and Other Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract." This standard aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The standard is effective for the Company in the first quarter of fiscal 2021, with early adoption permitted. The amendments in this standard may be applied on a retrospective or prospective basis. The Company intends to adopt the standard on a prospective basis in the first quarter of fiscal 2021. The prospective impact of the new guidance on the Company’s Consolidated Financial Statements will be dependent on the nature of future transactions within its scope. In August 2018, the FASB issued ASU No. 2018-14, "Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans." This standard modifies the disclosure requirements for employers that sponsor defined benefit pension or other post-retirement plans. This update removes disclosures that are not considered cost beneficial, clarifies certain required disclosures and adds additional disclosures. This standard is effective for the Company beginning in fiscal 2021, with early adoption permitted. The amendments in the standard need to be applied on a retrospective basis. The Company does not expect the adoption of the standard to result in material changes to its benefit plan disclosures. In August 2018, the FASB issued ASU No. 2018-13, "Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement." This standard modifies the disclosure requirements on fair value measurements by removing certain disclosures, modifying certain disclosures and adding additional disclosures. This standard is effective for the Company beginning in the first quarter of fiscal 2021. Certain disclosures in the standard need to be applied on a retrospective basis and others on a prospective basis. The Company does not expect the adoption of the standard to result in material changes to its fair value disclosures. In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." This standard, along with other guidance subsequently issued by the FASB, requires entities to estimate all expected credit losses for certain types of financial instruments, including trade receivables and contract assets, held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The standard also expands the disclosure requirements to enable users of financial statements to understand the entity's assumptions, models and methods for estimating expected credit losses. This standard is effective for the Company in the first quarter of fiscal 2021 on a modified retrospective basis. The Company does not expect the adoption of the standard to have a material impact on its Consolidated Financial Statements.

Emergence from Voluntary Reorga

Emergence from Voluntary Reorganization under Chapter 11 Proceedings	12 Months Ended
	Sep. 30, 2020
Reorganizations [Abstract]
Emergence from Voluntary Reorganization under Chapter 11 Proceedings	Emergence from Voluntary Reorganization under Chapter 11 Proceedings Plan of Reorganization On November 28, 2017, the Bankruptcy Court entered an order confirming the Plan of Reorganization. On the Emergence Date, the Plan of Reorganization became effective and the Debtors emerged from bankruptcy. On or following the Emergence Date and pursuant to the terms of the Plan of Reorganization, the following occurred: • Debtor-in-Possession Credit Agreement. The Company paid in full the debtor-in-possession credit agreement (the "DIP Credit Agreement") in the amount of $725 million; • Predecessor Equity and Indebtedness. The Debtors' obligations under stock certificates, equity interests and/or any other instrument or document directly or indirectly evidencing or creating any indebtedness or obligation of, or ownership interest in, the Debtors or giving rise to any claim or equity interest were canceled, except as provided under the Plan of Reorganization; • Successor Equity. The Company's certificate of incorporation was amended and restated to authorize the issuance of 605.0 million shares of Successor Company stock, consisting of 55.0 million shares of preferred stock, par value $0.01 per share, and 550.0 million shares of common stock, par value $0.01 per share, of which 110.0 million shares of common stock were issued (as discussed below); • Exit Financing. The Successor Company entered into (1) a term loan credit agreement with a principal amount of $2,925 million maturing on December 15, 2024, and (2) a $300 million asset-based revolving credit facility maturing on December 15, 2022; • First Lien Debt Claims. All of the Predecessor Company's outstanding obligations under the variable rate term B-3, B-4, B-6, and B-7 loans and the 7% and 9% senior secured notes (collectively, the "Predecessor first lien obligations") were canceled, and the holders of claims under the Predecessor first lien obligations received 99.3 million shares of Successor Company common stock. In addition, the holders of the Predecessor first lien obligations received cash in the amount of $2,061 million; • Second Lien Debt Claims. All the Predecessor Company's outstanding obligations under the 10.50% senior secured notes (the "Predecessor second lien obligations") were canceled, and the holders of claims under the Predecessor second lien obligations received 4.4 million shares of Successor Company common stock. In addition, holders of the Predecessor second lien obligations received warrants to purchase 5.6 million shares of Successor Company common stock at an exercise price of $25.55 per warrant; • Claims of Pension Benefit Guaranty Corporation ("PBGC"). The Predecessor Company's outstanding obligations under the Avaya Inc. Pension Plan for Salaried Employees ("APPSE") were terminated and transferred to the PBGC. The PBGC received 6.1 million shares of Successor Company common stock and $340 million in cash; and • General Unsecured Claims. Holders of the Predecessor Company's general unsecured claims were to receive their pro rata share of the general unsecured recovery pool. A liquidating trust was established in the amount of $58 million (comprised of cash and stock) for the benefit of the general unsecured claims. Included in the 110.0 million Successor Company common stock issued upon emergence were 0.2 million additional shares of common stock that were issued (but were not outstanding) for the benefit of the general unsecured creditors. Any excess cash and/or common stock not distributed to the general unsecured creditors was to be distributed to the holders of the Predecessor first lien obligations. Section 363 Asset Sale In connection with the Company's emergence from bankruptcy and in accordance with FASB ASC 852, "Reorganizations" ("ASC 852"), the Company applied the provisions of fresh start accounting to its Consolidated Financial Statements on the Emergence Date. The Company was required to use fresh start accounting since (i) the holders of existing voting shares of the Predecessor Company received less than 50% of the voting shares of the emerging entity and (ii) the reorganization value of the Company's assets immediately prior to confirmation of the Plan of Reorganization was less than the post-petition liabilities and allowed claims. ASC 852 prescribes that with the application of fresh start accounting, the Company allocated its reorganization value to its individual assets based on their estimated fair values in conformity with ASC 805, "Business Combinations". The reorganization value represents the fair value of the Successor Company's assets before considering liabilities. The excess reorganization value over the fair value of identified tangible and intangible assets is reported as goodwill. As a result of the application of fresh start accounting and the effects of the implementation of the Plan of Reorganization, the Consolidated Financial Statements after December 15, 2017 are not comparable with the Consolidated Financial Statements as of or prior to that date. Reorganization Value As set forth in the Plan of Reorganization, the agreed upon enterprise value of the Company was $5,721 million. This value was within the initial range calculated by the Company of approximately $5,100 million to approximately $7,100 million using an income approach. The $5,721 million enterprise value was selected as it was the transaction price agreed to in the global settlement agreement with the Company’s creditor constituencies, including the PBGC. The reorganization value was then determined by adding liabilities other than interest bearing debt, pension obligations and the deferred tax impact of the reorganization and fresh start adjustments. The following table reconciles the enterprise value to the estimated fair value of the Successor stockholders' equity as of the Emergence Date: (In millions, except per share amount) Enterprise value $ 5,721 Plus: Cash and cash equivalents 366 Less: Minimum cash required for operations (120) Fair value of Term Loan Credit Agreement (1) (2,896) Fair value of capitalized leases (20) Fair value of pension and other post-retirement obligations, net of tax (2) (856) Change in net deferred tax liabilities from reorganization (510) Fair value of Successor Emergence Date Warrants (3) (17) Fair value of Successor common stock $ 1,668 Shares issued at December 15, 2017 upon emergence 110.0 Successor common stock value per share $ 15.16 (1) The fair value of the Term Loan Credit Agreement was determined based on a market approach utilizing market-clearing data on the valuation date in addition to bid/ask prices and was estimated to be 99% of par value. (2) The following assumptions were used when measuring the fair value of the U.S. pension, non-U.S. pension, and post-retirement benefit plans: weighted-average return on assets of 7.75%, 3.80% and 5.90%, and weighted-average discount rate to measure plan obligations of 3.70%, 1.52% and 3.77%, respectively. (3) The fair value of the Emergence Date Warrants was estimated using the Black-Scholes pricing model. The following table reconciles the enterprise value to the estimated reorganization value as of the Emergence Date: (In millions) Enterprise value $ 5,721 Plus: Non-debt current liabilities 955 Non-debt non-current liabilities 2,090 Excess cash and cash equivalents 246 Less: Pension and other post-retirement obligations, net of deferred taxes (856) Capital lease obligations (20) Change in net deferred tax liabilities from reorganization (510) Emergence Date Warrants issued (17) Reorganization value of Successor assets $ 7,609 Consolidated Balance Sheet The adjustments set forth in the following consolidated balance sheet as of December 16, 2017 reflect the effect of the consummation of the transactions contemplated by the Plan of Reorganization (reflected in the column "Reorganization Adjustments") as well as fair value adjustments as a result of applying fresh start accounting (reflected in the column "Fresh Start Adjustments"). The explanatory notes highlight methods used to determine fair values or other amounts of the assets and liabilities, as well as significant assumptions or inputs. (In millions) Predecessor Company Reorganization Adjustments Fresh Start Adjustments Successor Company ASSETS Current assets: Cash and cash equivalents $ 770 $ (404) (1) $ — $ 366 Accounts receivable, net 497 — (106) (21) 391 Inventory 90 — 29 (22) 119 Other current assets 374 (58) (2) (66) (23) 250 TOTAL CURRENT ASSETS 1,731 (462) (143) 1,126 Property, plant and equipment, net 194 — 116 (24) 310 Deferred income taxes, net — 48 (3) (17) (25) 31 Intangible assets, net 298 — 3,137 (26) 3,435 Goodwill 3,541 — (883) (27) 2,658 Other assets 70 6 (4) (27) (28) 49 TOTAL ASSETS $ 5,834 $ (408) $ 2,183 $ 7,609 LIABILITIES Current liabilities: Debt maturing within one year $ 725 $ (696) (5) $ — $ 29 Accounts payable 325 (49) (6) — 276 Payroll and benefit obligations 123 23 (7) — 146 Deferred revenue 627 50 (8) (341) (29) 336 Business restructuring reserve 35 3 (9) — 38 Other current liabilities 97 65 (6,10) (3) (30) 159 TOTAL CURRENT LIABILITIES 1,932 (604) (344) 984 Non-current liabilities: Long-term debt, net of current portion — 2,771 (11) 96 (31) 2,867 Pension obligations 539 246 (12) — 785 Other post-retirement obligations — 212 (13) — 212 Deferred income taxes, net 28 113 (14) 548 (32) 689 Business restructuring reserve 26 4 (9) 4 (33) 34 Other liabilities 180 233 (8,15) (43) (29,34) 370 TOTAL NON-CURRENT LIABILITIES 773 3,579 605 4,957 LIABILITIES SUBJECT TO COMPROMISE 7,585 (7,585) (16) — — TOTAL LIABILITIES 10,290 (4,610) 261 5,941 Commitments and contingencies Equity awards on redeemable shares 6 (6) (17) — — Preferred stock: Series B 397 (397) (17) — — Series A 186 (186) (17) — — STOCKHOLDERS' (DEFICIT) EQUITY Common stock (Successor) — 1 (18) — 1 Additional paid-in capital (Successor) — 1,667 (18) — 1,667 Common stock (Predecessor) — — — — Additional paid-in capital (Predecessor) 2,387 (2,387) (17) — — (Accumulated deficit) retained earnings (5,978) 4,846 (19) 1,132 (36) — Accumulated other comprehensive (loss) income (1,454) 664 (20) 790 (35) — TOTAL STOCKHOLDERS' (DEFICIT) EQUITY (5,045) 4,791 1,922 1,668 TOTAL LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY $ 5,834 $ (408) $ 2,183 $ 7,609 Reorganization Adjustments In accordance with the Plan of Reorganization, the following adjustments were made: 1. Sources and Uses of Cash. The following reflects the net cash payments recorded as of the Emergence Date as a result of implementing the Plan of Reorganization: (In millions) Sources: Proceeds from Term Loan Credit Agreement, net of original issue discount $ 2,896 Release of restricted cash 76 Total sources of cash 2,972 Uses: Repayment of DIP Credit Agreement (725) Payment of DIP Credit Agreement accrued interest (1) Cash paid to Predecessor first lien debt-holders (2,061) Cash paid to PBGC (340) Payment for professional fees escrow account (56) Funding payment for Avaya represented employee pension plan (49) Payment of accrued professional and administrative fees (27) Costs incurred for Term Loan Credit Agreement and ABL Credit Agreement (59) Payment for general unsecured claims (58) Total uses of cash (3,376) Net uses of cash $ (404) 2. Other Current Assets. (In millions) Release of restricted cash $ (76) Reclassification of prepaid debt issuance costs related to the Term Loan Credit Agreement (42) Payment of fees related to the ABL Credit Agreement 5 Restricted cash for bankruptcy related professional fees 55 Total other current assets $ (58) 3. Deferred Income Taxes. The adjustment represents the release of the valuation allowance on deferred tax assets for certain non-U.S. subsidiaries which management believes more likely than not will be realized as a result of the bankruptcy reorganization. 4. Other Assets. The adjustment represents the re-establishment of foreign prepaid taxes. 5. Debt Maturing Within One Year. The adjustment represents the net effect of the Company’s repayment of $725 million for the DIP Credit Agreement and Term Loan Credit Agreement principal payments of $29 million due over the next year. 6. Accounts Payable . The net decrease of $49 million includes $50 million for professional fees that were reclassified to Other current liabilities for accrued bankruptcy related professional fees that were paid from an escrow account and a payment of $3 million of bankruptcy related professional fees, partially offset by reinstatement of $4 million contract cure costs from liabilities subject to compromise. 7. Payroll and Benefi t Obligations. The Company reinstated $23 million of liabilities subject to compromise related to the post-employment and post-retirement benefit obligations. 8. Deferred Revenue. The reinstatement of liabilities subject to compromise was $79 million of which $50 million is included in deferred revenue and $29 million in other liabilities. 9. Business Restructuring Reserve. The reinstatement of liabilities subject to compromise was $7 million, of which $3 million is current and $4 million is non-current. 10. Other Current Liabilities. (In millions) Reclassification of accrued bankruptcy related professional fees $ 50 Reinstatement of other current liabilities 16 Payment of accrued interest on the DIP Credit Agreement (1) Total other current liabilities $ 65 11. Exit Financing. In accordance with the Plan of Reorganization, the Company entered into the Term Loan Credit Agreement with a principal amount of $2,925 million, and the ABL Credit Agreement, which allows borrowings up to an aggregate principal amount of $300 million, subject to borrowing base availability. (In millions) Term Loan Credit Agreement $ 2,925 Less: Discount (29) Upfront and underwriting fees (54) Cash received upon emergence from bankruptcy 2,842 Reclassification of debt issuance costs incurred prior to emergence from bankruptcy (42) Current portion of Long-term debt (29) Long-term debt, net of current portion $ 2,771 12. Pension Obligations. In accordance with the Plan of Reorganization, the Company reinstated from liabilities subject to compromise $295 million related to the Avaya Pension Plan for represented employees and also contributed $49 million to the related pension trust. 13. Other Post-retirement Obligations. Other post-retirement benefit obligations of $212 million were reinstated from liabilities subject to compromise. 14. Deferred Income Taxes . The adjustment represents the reinstatement of the deferred tax liability that was included in liabilities subject to compromise. 15. Other Liabilities . The increase of $233 million primarily relates to the reinstatement of employee benefits, tax liabilities and deferred revenue from liabilities subject to compromise. Also included is the value of the Emergence Date Warrants issued to the holders of the Predecessor second lien obligations. 16. Liabilities Subject to Compromise. Liabilities subject to compromise were reinstated or settled as follows in accordance with the Plan of Reorganization: (In millions) Liabilities subject to compromise $ 7,585 Less amounts settled per the Plan of Reorganization Pre-petition first lien debt (4,281) Pre-petition second lien debt (1,440) Avaya Pension Plan for Salaried Employees (620) Amounts reinstated: Accounts payable (4) Payroll and benefit obligations (23) Deferred revenue (50) Business restructuring reserves (7) Other current liabilities (16) Pension obligations (295) Other post-retirement obligations (212) Deferred income taxes, net (118) Other liabilities (216) Total liabilities reinstated at emergence (941) General unsecured credit claims (1) (303) Liabilities subject to compromise $ — (1) In settlement of allowed general unsecured claims, each claimant will receive a pro-rata distribution of $58 million of the general unsecured claims account. The following table displays the detail on the gain on settlement of liabilities subject to compromise: (In millions) Pre-petition first lien debt $ 711 Pre-petition second lien debt 1,356 Avaya pension plan for salaried employees (516) General unsecured creditors' claims 227 Net gain on settlement of Liabilities subject to compromise $ 1,778 17. Cancellation of Predecessor Preferred and Common Stock. All common stock, Series A and B preferred stock and all other equity awards of the Predecessor Company were canceled on the Emergence Date without any recovery on account thereof. 18. Issuance of Successor Common Stock and Emergence Date Warrants. In settlement of the Company's $5,721 million Predecessor first lien obligations and Predecessor second lien obligations, the holders of the Predecessor first lien obligations received a total of 99.3 million shares of common stock (fair value of $1,509 million) and $2,061 million in cash and the holders of the Predecessor second lien obligations received a total of 4.4 million shares of common stock (fair value of $67 million) and 5.6 million Emergence Date Warrants to purchase a like amount of common shares (fair value of $17 million). In addition, as part of the Plan of Reorganization, the Company completed a distressed termination of the APPSE in accordance with a stipulation settlement with the PBGC, the PBGC received $340 million in cash and 6.1 million shares of common stock (fair value of $92 million). 19. Accumulated Deficit. (In millions) Accumulated deficit: Net gain on settlement of liabilities subject to compromise $ 1,778 Expense for certain professional fees (26) Benefit from income taxes 118 Cancellation of Predecessor equity awards 6 Cancellation of Predecessor Preferred stock Series B 397 Cancellation of Predecessor Preferred stock Series A 186 Cancellation of Predecessor Common stock 2,387 Total $ 4,846 20. Accumulated Comprehensive Loss. The changes to Accumulated comprehensive loss relate to the settlement of the APPSE and the Avaya Supplemental Pension Plan ("ASPP") and the associated taxes. Fresh Start Adjustments At the Emergence Date, the Company met the requirements under ASC 852 for the adoption of fresh start accounting. These adjustments reflect actual amounts recorded as of the Emergence Date. 21. Accounts Receivable. This adjustment relates to a change in accounting policy for the way the Company will present uncollected deferred revenue upon emergence from bankruptcy. The Company offset such deferred revenue against the related account receivable. 22. Inventory . This adjustment relates to the write-up of inventory to fair value based on estimated selling prices, less costs of disposal. 23. Other Current Assets . This adjustment reflects the write-off of certain prepaid commissions, deferred installation costs and debt issuance costs that do not meet the definition of an asset upon emergence. 24. Property, Plant and Equipment . An adjustment of $116 million was recorded to increase the net book value of property, plant and equipment to its estimated fair value based on estimated current acquisition price, plus costs to make the property fully operational. (In millions) Buildings and improvements $ 82 Machinery and equipment 38 Rental equipment 85 Assets under construction 13 Internal use software 92 Total property, plant and equipment 310 Less: accumulated depreciation and amortization — Property, plant and equipment, net $ 310 25. Deferred Income Tax. T he adjustment represents the release of the valuation allowance on deferred tax assets for certain non-U.S. subsidiaries which management believes more likely than not will be realized as a result of future taxable income from the reversal of deferred tax liabilities that were established as part of fresh start accounting. 26. Intangible Assets. The Company recorded an adjustment to intangible assets for $3,137 million as follows: Successor Predecessor (In millions) December 15, 2017 Post-emergence December 15, 2017 Pre-emergence Difference Customer relationships and other intangible assets $ 2,155 $ 96 $ 2,059 Technology and patents 905 12 893 Trademarks and trade names 375 190 185 Total $ 3,435 $ 298 $ 3,137 The fair value of customer relationships was determined using the excess earnings method, a derivation of the income approach that calculates residual profit attributable to an asset after proper returns are paid to complementary or contributory assets. The fair value of technology and patents and trademarks and trade names was determined using the royalty savings method, a derivation of the income approach that estimates the royalties saved through ownership of the assets. 27. Goodwill. Predecessor Company goodwill of $3,541 million was eliminated and Successor Company goodwill of $2,658 million was established based on the calculated reorganization value. (In millions) Reorganization value of Successor Company $ 7,609 Less: Fair value of Successor Company assets (4,951) Reorganization value of Successor Company assets in excess of fair value - Goodwill $ 2,658 28. Other Assets. The $27 million decrease to other assets is related to prepaid commissions that do not meet the definition of an asset upon emergence as there is no future benefit to the Successor Company. 29. Deferred Revenue. The fair value of deferred revenue, which principally relates to payments on annual maintenance contracts, was determined by deducting selling costs and associated profit from the Predecessor Company deferred revenue balance to arrive at the costs and profit associated with fulfilling the liability. Additionally, the decrease includes the impact of an accounting policy change whereby the Successor Company no longer recognizes deferred revenue relating to sales transactions that have been billed, but for which the related account receivable has not yet been collected. 30. Other Current Liabilities. The decrease of $3 million to other current liabilities is related to the fair value of real estate leases determined to be above or below market using the income approach based on the difference between the contractual rental rate and the estimated market rental rate, discounted utilizing a risk-related discount rate. 31. Long-term Debt . The fair value of the Term Loan Credit Agreement was determined based on a market approach utilizing market-clearing data on the valuation date in addition to bid/ask prices. 32. Deferred Income Taxes. The adjustment represents the establishment of deferred tax liabilities related to book/tax differences created by fresh start accounting adjustments. The amount is net of the release of the valuation allowance on deferred tax assets, which management believes more likely than not will be realized as a result of future taxable income from the reversal of such deferred tax liabilities. 33. Business Restructuring Reserve. The Company recorded an increase to its non-current business restructuring reserves based on estimated future cash flows applied to a current discount rate at emergence. 34. Other Liabilities. A decrease in other liabilities of $43 million relates to deferred revenue and real estate leases as previously discussed. 35. Accumulated Other Comprehensive Loss. The remaining balance in Accumulated comprehensive loss was reversed to Reorganization expenses, net. 36. Fresh Start Adjustments. The following table reflects the cumulative impact of the fresh start adjustments as discussed above, the elimination of the Predecessor Company's accumulated other comprehensive loss and the adjustments required to eliminate accumulated deficit: (In millions) Eliminate Predecessor Intangible assets $ (298) Eliminate Predecessor Goodwill (3,541) Establish Successor Intangible assets 3,435 Establish Successor Goodwill 2,658 Fair value adjustment to Inventory 29 Fair value adjustment to Other current assets (66) Fair value adjustment to Property, plant and equipment 116 Fair value adjustment to Other assets (27) Fair value adjustment to Deferred revenue 235 Fair value adjustment to Business restructuring reserves (4) Fair value adjustment to Other current liabilities 3 Fair value adjustment to Long-term debt (96) Fair value adjustment to Other liabilities 43 Release Predecessor Accumulated comprehensive loss (790) Fresh start adjustments included in Reorganization items, net 1,697 Tax impact of fresh start adjustments (565) Gain on fresh start accounting, net $ 1,132

Fresh Start Accounting

Fresh Start Accounting	12 Months Ended
	Sep. 30, 2020
Reorganizations [Abstract]
Fresh Start Accounting	Emergence from Voluntary Reorganization under Chapter 11 Proceedings Plan of Reorganization On November 28, 2017, the Bankruptcy Court entered an order confirming the Plan of Reorganization. On the Emergence Date, the Plan of Reorganization became effective and the Debtors emerged from bankruptcy. On or following the Emergence Date and pursuant to the terms of the Plan of Reorganization, the following occurred: • Debtor-in-Possession Credit Agreement. The Company paid in full the debtor-in-possession credit agreement (the "DIP Credit Agreement") in the amount of $725 million; • Predecessor Equity and Indebtedness. The Debtors' obligations under stock certificates, equity interests and/or any other instrument or document directly or indirectly evidencing or creating any indebtedness or obligation of, or ownership interest in, the Debtors or giving rise to any claim or equity interest were canceled, except as provided under the Plan of Reorganization; • Successor Equity. The Company's certificate of incorporation was amended and restated to authorize the issuance of 605.0 million shares of Successor Company stock, consisting of 55.0 million shares of preferred stock, par value $0.01 per share, and 550.0 million shares of common stock, par value $0.01 per share, of which 110.0 million shares of common stock were issued (as discussed below); • Exit Financing. The Successor Company entered into (1) a term loan credit agreement with a principal amount of $2,925 million maturing on December 15, 2024, and (2) a $300 million asset-based revolving credit facility maturing on December 15, 2022; • First Lien Debt Claims. All of the Predecessor Company's outstanding obligations under the variable rate term B-3, B-4, B-6, and B-7 loans and the 7% and 9% senior secured notes (collectively, the "Predecessor first lien obligations") were canceled, and the holders of claims under the Predecessor first lien obligations received 99.3 million shares of Successor Company common stock. In addition, the holders of the Predecessor first lien obligations received cash in the amount of $2,061 million; • Second Lien Debt Claims. All the Predecessor Company's outstanding obligations under the 10.50% senior secured notes (the "Predecessor second lien obligations") were canceled, and the holders of claims under the Predecessor second lien obligations received 4.4 million shares of Successor Company common stock. In addition, holders of the Predecessor second lien obligations received warrants to purchase 5.6 million shares of Successor Company common stock at an exercise price of $25.55 per warrant; • Claims of Pension Benefit Guaranty Corporation ("PBGC"). The Predecessor Company's outstanding obligations under the Avaya Inc. Pension Plan for Salaried Employees ("APPSE") were terminated and transferred to the PBGC. The PBGC received 6.1 million shares of Successor Company common stock and $340 million in cash; and • General Unsecured Claims. Holders of the Predecessor Company's general unsecured claims were to receive their pro rata share of the general unsecured recovery pool. A liquidating trust was established in the amount of $58 million (comprised of cash and stock) for the benefit of the general unsecured claims. Included in the 110.0 million Successor Company common stock issued upon emergence were 0.2 million additional shares of common stock that were issued (but were not outstanding) for the benefit of the general unsecured creditors. Any excess cash and/or common stock not distributed to the general unsecured creditors was to be distributed to the holders of the Predecessor first lien obligations. Section 363 Asset Sale In connection with the Company's emergence from bankruptcy and in accordance with FASB ASC 852, "Reorganizations" ("ASC 852"), the Company applied the provisions of fresh start accounting to its Consolidated Financial Statements on the Emergence Date. The Company was required to use fresh start accounting since (i) the holders of existing voting shares of the Predecessor Company received less than 50% of the voting shares of the emerging entity and (ii) the reorganization value of the Company's assets immediately prior to confirmation of the Plan of Reorganization was less than the post-petition liabilities and allowed claims. ASC 852 prescribes that with the application of fresh start accounting, the Company allocated its reorganization value to its individual assets based on their estimated fair values in conformity with ASC 805, "Business Combinations". The reorganization value represents the fair value of the Successor Company's assets before considering liabilities. The excess reorganization value over the fair value of identified tangible and intangible assets is reported as goodwill. As a result of the application of fresh start accounting and the effects of the implementation of the Plan of Reorganization, the Consolidated Financial Statements after December 15, 2017 are not comparable with the Consolidated Financial Statements as of or prior to that date. Reorganization Value As set forth in the Plan of Reorganization, the agreed upon enterprise value of the Company was $5,721 million. This value was within the initial range calculated by the Company of approximately $5,100 million to approximately $7,100 million using an income approach. The $5,721 million enterprise value was selected as it was the transaction price agreed to in the global settlement agreement with the Company’s creditor constituencies, including the PBGC. The reorganization value was then determined by adding liabilities other than interest bearing debt, pension obligations and the deferred tax impact of the reorganization and fresh start adjustments. The following table reconciles the enterprise value to the estimated fair value of the Successor stockholders' equity as of the Emergence Date: (In millions, except per share amount) Enterprise value $ 5,721 Plus: Cash and cash equivalents 366 Less: Minimum cash required for operations (120) Fair value of Term Loan Credit Agreement (1) (2,896) Fair value of capitalized leases (20) Fair value of pension and other post-retirement obligations, net of tax (2) (856) Change in net deferred tax liabilities from reorganization (510) Fair value of Successor Emergence Date Warrants (3) (17) Fair value of Successor common stock $ 1,668 Shares issued at December 15, 2017 upon emergence 110.0 Successor common stock value per share $ 15.16 (1) The fair value of the Term Loan Credit Agreement was determined based on a market approach utilizing market-clearing data on the valuation date in addition to bid/ask prices and was estimated to be 99% of par value. (2) The following assumptions were used when measuring the fair value of the U.S. pension, non-U.S. pension, and post-retirement benefit plans: weighted-average return on assets of 7.75%, 3.80% and 5.90%, and weighted-average discount rate to measure plan obligations of 3.70%, 1.52% and 3.77%, respectively. (3) The fair value of the Emergence Date Warrants was estimated using the Black-Scholes pricing model. The following table reconciles the enterprise value to the estimated reorganization value as of the Emergence Date: (In millions) Enterprise value $ 5,721 Plus: Non-debt current liabilities 955 Non-debt non-current liabilities 2,090 Excess cash and cash equivalents 246 Less: Pension and other post-retirement obligations, net of deferred taxes (856) Capital lease obligations (20) Change in net deferred tax liabilities from reorganization (510) Emergence Date Warrants issued (17) Reorganization value of Successor assets $ 7,609 Consolidated Balance Sheet The adjustments set forth in the following consolidated balance sheet as of December 16, 2017 reflect the effect of the consummation of the transactions contemplated by the Plan of Reorganization (reflected in the column "Reorganization Adjustments") as well as fair value adjustments as a result of applying fresh start accounting (reflected in the column "Fresh Start Adjustments"). The explanatory notes highlight methods used to determine fair values or other amounts of the assets and liabilities, as well as significant assumptions or inputs. (In millions) Predecessor Company Reorganization Adjustments Fresh Start Adjustments Successor Company ASSETS Current assets: Cash and cash equivalents $ 770 $ (404) (1) $ — $ 366 Accounts receivable, net 497 — (106) (21) 391 Inventory 90 — 29 (22) 119 Other current assets 374 (58) (2) (66) (23) 250 TOTAL CURRENT ASSETS 1,731 (462) (143) 1,126 Property, plant and equipment, net 194 — 116 (24) 310 Deferred income taxes, net — 48 (3) (17) (25) 31 Intangible assets, net 298 — 3,137 (26) 3,435 Goodwill 3,541 — (883) (27) 2,658 Other assets 70 6 (4) (27) (28) 49 TOTAL ASSETS $ 5,834 $ (408) $ 2,183 $ 7,609 LIABILITIES Current liabilities: Debt maturing within one year $ 725 $ (696) (5) $ — $ 29 Accounts payable 325 (49) (6) — 276 Payroll and benefit obligations 123 23 (7) — 146 Deferred revenue 627 50 (8) (341) (29) 336 Business restructuring reserve 35 3 (9) — 38 Other current liabilities 97 65 (6,10) (3) (30) 159 TOTAL CURRENT LIABILITIES 1,932 (604) (344) 984 Non-current liabilities: Long-term debt, net of current portion — 2,771 (11) 96 (31) 2,867 Pension obligations 539 246 (12) — 785 Other post-retirement obligations — 212 (13) — 212 Deferred income taxes, net 28 113 (14) 548 (32) 689 Business restructuring reserve 26 4 (9) 4 (33) 34 Other liabilities 180 233 (8,15) (43) (29,34) 370 TOTAL NON-CURRENT LIABILITIES 773 3,579 605 4,957 LIABILITIES SUBJECT TO COMPROMISE 7,585 (7,585) (16) — — TOTAL LIABILITIES 10,290 (4,610) 261 5,941 Commitments and contingencies Equity awards on redeemable shares 6 (6) (17) — — Preferred stock: Series B 397 (397) (17) — — Series A 186 (186) (17) — — STOCKHOLDERS' (DEFICIT) EQUITY Common stock (Successor) — 1 (18) — 1 Additional paid-in capital (Successor) — 1,667 (18) — 1,667 Common stock (Predecessor) — — — — Additional paid-in capital (Predecessor) 2,387 (2,387) (17) — — (Accumulated deficit) retained earnings (5,978) 4,846 (19) 1,132 (36) — Accumulated other comprehensive (loss) income (1,454) 664 (20) 790 (35) — TOTAL STOCKHOLDERS' (DEFICIT) EQUITY (5,045) 4,791 1,922 1,668 TOTAL LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY $ 5,834 $ (408) $ 2,183 $ 7,609 Reorganization Adjustments In accordance with the Plan of Reorganization, the following adjustments were made: 1. Sources and Uses of Cash. The following reflects the net cash payments recorded as of the Emergence Date as a result of implementing the Plan of Reorganization: (In millions) Sources: Proceeds from Term Loan Credit Agreement, net of original issue discount $ 2,896 Release of restricted cash 76 Total sources of cash 2,972 Uses: Repayment of DIP Credit Agreement (725) Payment of DIP Credit Agreement accrued interest (1) Cash paid to Predecessor first lien debt-holders (2,061) Cash paid to PBGC (340) Payment for professional fees escrow account (56) Funding payment for Avaya represented employee pension plan (49) Payment of accrued professional and administrative fees (27) Costs incurred for Term Loan Credit Agreement and ABL Credit Agreement (59) Payment for general unsecured claims (58) Total uses of cash (3,376) Net uses of cash $ (404) 2. Other Current Assets. (In millions) Release of restricted cash $ (76) Reclassification of prepaid debt issuance costs related to the Term Loan Credit Agreement (42) Payment of fees related to the ABL Credit Agreement 5 Restricted cash for bankruptcy related professional fees 55 Total other current assets $ (58) 3. Deferred Income Taxes. The adjustment represents the release of the valuation allowance on deferred tax assets for certain non-U.S. subsidiaries which management believes more likely than not will be realized as a result of the bankruptcy reorganization. 4. Other Assets. The adjustment represents the re-establishment of foreign prepaid taxes. 5. Debt Maturing Within One Year. The adjustment represents the net effect of the Company’s repayment of $725 million for the DIP Credit Agreement and Term Loan Credit Agreement principal payments of $29 million due over the next year. 6. Accounts Payable . The net decrease of $49 million includes $50 million for professional fees that were reclassified to Other current liabilities for accrued bankruptcy related professional fees that were paid from an escrow account and a payment of $3 million of bankruptcy related professional fees, partially offset by reinstatement of $4 million contract cure costs from liabilities subject to compromise. 7. Payroll and Benefi t Obligations. The Company reinstated $23 million of liabilities subject to compromise related to the post-employment and post-retirement benefit obligations. 8. Deferred Revenue. The reinstatement of liabilities subject to compromise was $79 million of which $50 million is included in deferred revenue and $29 million in other liabilities. 9. Business Restructuring Reserve. The reinstatement of liabilities subject to compromise was $7 million, of which $3 million is current and $4 million is non-current. 10. Other Current Liabilities. (In millions) Reclassification of accrued bankruptcy related professional fees $ 50 Reinstatement of other current liabilities 16 Payment of accrued interest on the DIP Credit Agreement (1) Total other current liabilities $ 65 11. Exit Financing. In accordance with the Plan of Reorganization, the Company entered into the Term Loan Credit Agreement with a principal amount of $2,925 million, and the ABL Credit Agreement, which allows borrowings up to an aggregate principal amount of $300 million, subject to borrowing base availability. (In millions) Term Loan Credit Agreement $ 2,925 Less: Discount (29) Upfront and underwriting fees (54) Cash received upon emergence from bankruptcy 2,842 Reclassification of debt issuance costs incurred prior to emergence from bankruptcy (42) Current portion of Long-term debt (29) Long-term debt, net of current portion $ 2,771 12. Pension Obligations. In accordance with the Plan of Reorganization, the Company reinstated from liabilities subject to compromise $295 million related to the Avaya Pension Plan for represented employees and also contributed $49 million to the related pension trust. 13. Other Post-retirement Obligations. Other post-retirement benefit obligations of $212 million were reinstated from liabilities subject to compromise. 14. Deferred Income Taxes . The adjustment represents the reinstatement of the deferred tax liability that was included in liabilities subject to compromise. 15. Other Liabilities . The increase of $233 million primarily relates to the reinstatement of employee benefits, tax liabilities and deferred revenue from liabilities subject to compromise. Also included is the value of the Emergence Date Warrants issued to the holders of the Predecessor second lien obligations. 16. Liabilities Subject to Compromise. Liabilities subject to compromise were reinstated or settled as follows in accordance with the Plan of Reorganization: (In millions) Liabilities subject to compromise $ 7,585 Less amounts settled per the Plan of Reorganization Pre-petition first lien debt (4,281) Pre-petition second lien debt (1,440) Avaya Pension Plan for Salaried Employees (620) Amounts reinstated: Accounts payable (4) Payroll and benefit obligations (23) Deferred revenue (50) Business restructuring reserves (7) Other current liabilities (16) Pension obligations (295) Other post-retirement obligations (212) Deferred income taxes, net (118) Other liabilities (216) Total liabilities reinstated at emergence (941) General unsecured credit claims (1) (303) Liabilities subject to compromise $ — (1) In settlement of allowed general unsecured claims, each claimant will receive a pro-rata distribution of $58 million of the general unsecured claims account. The following table displays the detail on the gain on settlement of liabilities subject to compromise: (In millions) Pre-petition first lien debt $ 711 Pre-petition second lien debt 1,356 Avaya pension plan for salaried employees (516) General unsecured creditors' claims 227 Net gain on settlement of Liabilities subject to compromise $ 1,778 17. Cancellation of Predecessor Preferred and Common Stock. All common stock, Series A and B preferred stock and all other equity awards of the Predecessor Company were canceled on the Emergence Date without any recovery on account thereof. 18. Issuance of Successor Common Stock and Emergence Date Warrants. In settlement of the Company's $5,721 million Predecessor first lien obligations and Predecessor second lien obligations, the holders of the Predecessor first lien obligations received a total of 99.3 million shares of common stock (fair value of $1,509 million) and $2,061 million in cash and the holders of the Predecessor second lien obligations received a total of 4.4 million shares of common stock (fair value of $67 million) and 5.6 million Emergence Date Warrants to purchase a like amount of common shares (fair value of $17 million). In addition, as part of the Plan of Reorganization, the Company completed a distressed termination of the APPSE in accordance with a stipulation settlement with the PBGC, the PBGC received $340 million in cash and 6.1 million shares of common stock (fair value of $92 million). 19. Accumulated Deficit. (In millions) Accumulated deficit: Net gain on settlement of liabilities subject to compromise $ 1,778 Expense for certain professional fees (26) Benefit from income taxes 118 Cancellation of Predecessor equity awards 6 Cancellation of Predecessor Preferred stock Series B 397 Cancellation of Predecessor Preferred stock Series A 186 Cancellation of Predecessor Common stock 2,387 Total $ 4,846 20. Accumulated Comprehensive Loss. The changes to Accumulated comprehensive loss relate to the settlement of the APPSE and the Avaya Supplemental Pension Plan ("ASPP") and the associated taxes. Fresh Start Adjustments At the Emergence Date, the Company met the requirements under ASC 852 for the adoption of fresh start accounting. These adjustments reflect actual amounts recorded as of the Emergence Date. 21. Accounts Receivable. This adjustment relates to a change in accounting policy for the way the Company will present uncollected deferred revenue upon emergence from bankruptcy. The Company offset such deferred revenue against the related account receivable. 22. Inventory . This adjustment relates to the write-up of inventory to fair value based on estimated selling prices, less costs of disposal. 23. Other Current Assets . This adjustment reflects the write-off of certain prepaid commissions, deferred installation costs and debt issuance costs that do not meet the definition of an asset upon emergence. 24. Property, Plant and Equipment . An adjustment of $116 million was recorded to increase the net book value of property, plant and equipment to its estimated fair value based on estimated current acquisition price, plus costs to make the property fully operational. (In millions) Buildings and improvements $ 82 Machinery and equipment 38 Rental equipment 85 Assets under construction 13 Internal use software 92 Total property, plant and equipment 310 Less: accumulated depreciation and amortization — Property, plant and equipment, net $ 310 25. Deferred Income Tax. T he adjustment represents the release of the valuation allowance on deferred tax assets for certain non-U.S. subsidiaries which management believes more likely than not will be realized as a result of future taxable income from the reversal of deferred tax liabilities that were established as part of fresh start accounting. 26. Intangible Assets. The Company recorded an adjustment to intangible assets for $3,137 million as follows: Successor Predecessor (In millions) December 15, 2017 Post-emergence December 15, 2017 Pre-emergence Difference Customer relationships and other intangible assets $ 2,155 $ 96 $ 2,059 Technology and patents 905 12 893 Trademarks and trade names 375 190 185 Total $ 3,435 $ 298 $ 3,137 The fair value of customer relationships was determined using the excess earnings method, a derivation of the income approach that calculates residual profit attributable to an asset after proper returns are paid to complementary or contributory assets. The fair value of technology and patents and trademarks and trade names was determined using the royalty savings method, a derivation of the income approach that estimates the royalties saved through ownership of the assets. 27. Goodwill. Predecessor Company goodwill of $3,541 million was eliminated and Successor Company goodwill of $2,658 million was established based on the calculated reorganization value. (In millions) Reorganization value of Successor Company $ 7,609 Less: Fair value of Successor Company assets (4,951) Reorganization value of Successor Company assets in excess of fair value - Goodwill $ 2,658 28. Other Assets. The $27 million decrease to other assets is related to prepaid commissions that do not meet the definition of an asset upon emergence as there is no future benefit to the Successor Company. 29. Deferred Revenue. The fair value of deferred revenue, which principally relates to payments on annual maintenance contracts, was determined by deducting selling costs and associated profit from the Predecessor Company deferred revenue balance to arrive at the costs and profit associated with fulfilling the liability. Additionally, the decrease includes the impact of an accounting policy change whereby the Successor Company no longer recognizes deferred revenue relating to sales transactions that have been billed, but for which the related account receivable has not yet been collected. 30. Other Current Liabilities. The decrease of $3 million to other current liabilities is related to the fair value of real estate leases determined to be above or below market using the income approach based on the difference between the contractual rental rate and the estimated market rental rate, discounted utilizing a risk-related discount rate. 31. Long-term Debt . The fair value of the Term Loan Credit Agreement was determined based on a market approach utilizing market-clearing data on the valuation date in addition to bid/ask prices. 32. Deferred Income Taxes. The adjustment represents the establishment of deferred tax liabilities related to book/tax differences created by fresh start accounting adjustments. The amount is net of the release of the valuation allowance on deferred tax assets, which management believes more likely than not will be realized as a result of future taxable income from the reversal of such deferred tax liabilities. 33. Business Restructuring Reserve. The Company recorded an increase to its non-current business restructuring reserves based on estimated future cash flows applied to a current discount rate at emergence. 34. Other Liabilities. A decrease in other liabilities of $43 million relates to deferred revenue and real estate leases as previously discussed. 35. Accumulated Other Comprehensive Loss. The remaining balance in Accumulated comprehensive loss was reversed to Reorganization expenses, net. 36. Fresh Start Adjustments. The following table reflects the cumulative impact of the fresh start adjustments as discussed above, the elimination of the Predecessor Company's accumulated other comprehensive loss and the adjustments required to eliminate accumulated deficit: (In millions) Eliminate Predecessor Intangible assets $ (298) Eliminate Predecessor Goodwill (3,541) Establish Successor Intangible assets 3,435 Establish Successor Goodwill 2,658 Fair value adjustment to Inventory 29 Fair value adjustment to Other current assets (66) Fair value adjustment to Property, plant and equipment 116 Fair value adjustment to Other assets (27) Fair value adjustment to Deferred revenue 235 Fair value adjustment to Business restructuring reserves (4) Fair value adjustment to Other current liabilities 3 Fair value adjustment to Long-term debt (96) Fair value adjustment to Other liabilities 43 Release Predecessor Accumulated comprehensive loss (790) Fresh start adjustments included in Reorganization items, net 1,697 Tax impact of fresh start adjustments (565) Gain on fresh start accounting, net $ 1,132

Revenue Recognition

Revenue Recognition	12 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Disaggregation of Revenue The following tables provide the Company's disaggregated revenue for fiscal 2020 and 2019: Fiscal years ended September 30, (In millions) 2020 2019 Revenue: Products & Solutions $ 1,074 $ 1,228 Services 1,805 1,680 Unallocated Amounts (6) (21) $ 2,873 $ 2,887 Fiscal year ended September 30, 2020 (In millions) Products & Solutions Services Unallocated Total Revenue: U.S. $ 546 $ 1,097 $ (3) $ 1,640 International: Europe, Middle East and Africa 327 389 (2) 714 Asia Pacific 122 175 (1) 296 Americas International - Canada and Latin America 79 144 — 223 Total International 528 708 (3) 1,233 Total revenue $ 1,074 $ 1,805 $ (6) $ 2,873 Fiscal year ended September 30, 2019 (In millions) Products & Solutions Services Unallocated Total Revenue: U.S. $ 585 $ 981 $ (13) $ 1,553 International: Europe, Middle East and Africa 381 375 (3) 753 Asia Pacific 155 175 (3) 327 Americas International - Canada and Latin America 107 149 (2) 254 Total International 643 699 (8) 1,334 Total revenue $ 1,228 $ 1,680 $ (21) $ 2,887 Unallocated amounts represent the fair value adjustment to deferred revenue recognized upon emergence from bankruptcy and excluded from segment revenue. Transaction Price Allocated to the Remaining Performance Obligations The transaction price allocated to remaining performance obligations that were wholly or partially unsatisfied as of September 30, 2020 was $2.4 billion, of which 57% and 26% is expected to be recognized within 12 months and 13-24 months, respectively, with the remaining balance expected to be recognized thereafter. This excludes amounts for remaining performance obligations that are (1) for contracts recognized over time using the "right to invoice" practical expedient, (2) related to sales or usage based royalties promised in exchange for a license of intellectual property and (3) related to variable consideration allocated entirely to a wholly unsatisfied performance obligation. Contract Balances The following table provides information about accounts receivable, contract assets and contract liabilities for the periods presented: As of September 30, (In millions) 2020 2019 Increase (Decrease) Accounts receivable, net $ 275 $ 314 $ (39) Contract assets: Current $ 296 $ 187 $ 109 Non-current (Other assets) 71 16 55 $ 367 $ 203 $ 164 Cost of obtaining a contract: Current (Contract costs) $ 92 $ 89 $ 3 Non-current (Other assets) 40 45 (5) $ 132 $ 134 $ (2) Cost to fulfill a contract: Current (Contract costs) $ 23 $ 25 $ (2) Contract liabilities: Current $ 446 $ 472 $ (26) Non-current 373 78 295 $ 819 $ 550 $ 269 The increase in Contract assets was mainly driven by growth in the Company's subscription offerings. The increase in Contract liabilities was mainly driven by consideration received in connection with the strategic partnership with RingCentral, Inc. ("RingCentral") as discussed in Note 6, "Business Combinations and Strategic Partnerships and Investments." The Company did not record any asset impairment charges related to contract assets during fiscal 2020 and 2019. During fiscal 2020 and 2019, the Company recognized revenue of $546 million and $537 million that had been previously recorded as a Contract liability as of October 1, 2019 and 2018, respectively. As a result of contract modifications during fiscal 2020, the Company recorded adjustments to reduce revenue by $1 million for performance obligations that were satisfied in prior periods. During fiscal 2019, no adjustments were recorded to revenue related to performance obligations that were satisfied in prior periods. Contract Costs During fiscal 2020, the Company recognized $156 million for amortization of costs to obtain customer contracts, of which $152 million was included in Selling, general and administrative expense and the remaining $4 million was a reduction to Revenue. During fiscal 2019, the Company recognized $103 million for amortization of costs to obtain customer contracts, of which $100 million was included in Selling, general and administrative expense and the remaining $3 million was a reduction to Revenue. During fiscal 2020, the Company recognized $52 million of contract fulfillment costs, of which $48 million was included within Costs and the remaining $4 million was a reduction to Revenue. During fiscal 2019, the Company recognized $50 million of contract fulfillment costs within Costs.

Leases, Codification Topic 842

Leases, Codification Topic 842	12 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases of Lessee Disclosure	Leases The following table details the components of net lease expense for fiscal 2020: (In millions) Fiscal year ended Operating lease cost (1) $ 67 Short-term lease cost (1) 5 Variable lease cost (1)(2) 17 Finance lease amortization of right-of-use assets (1) 4 Sublease income (3) (5) Total lease cost $ 88 (1) Allocated between Cost of products and services, and Operating expenses. (2) Includes real estate taxes and other charges for non-lease services payable to lessors and recognized in the period incurred. (3) Included in Other income, net. The Company's right-of-use assets and lease liabilities for financing leases are included in the Consolidated Balance Sheet as follows: (In millions) September 30, 2020 ASSETS Property, plant and equipment, net $ 12 LIABILITIES Other current liabilities 8 Other liabilities 9 The following table presents the Company's annual maturity of lease payments, weighted average remaining lease term and weighted average interest rate for operating and financing leases as of September 30, 2020: (In millions) Operating Leases Financing Leases 2021 58 9 2022 49 4 2023 36 3 2024 25 2 2025 14 — 2026 and thereafter 22 — Total lease payments 204 18 Less: imputed interest (26) (1) Total lease liability $ 178 $ 17 Weighted average remaining lease term 4.5 years 2.7 years Weighted average interest rate 6.1 % 5.4 % The following table presents the Company's future minimum lease payments under non-cancelable leases as of September 30, 2019, which was prior to the adoption of ASC 842: In millions Operating Leases Capital Leases 2020 $ 51 $ 12 2021 39 6 2022 33 2 2023 22 — 2024 17 — 2025 and thereafter 29 — Total lease payments $ 191 20 Less: imputed interest (1) Total lease liability $ 19 The capital lease obligation as of September 30, 2019 included $11 million and $8 million within Other current liabilities and Other liabilities, respectively. The Company outsources certain delivery services associated with its enterprise cloud and managed services, which included the sale of specified assets owned by the Company that were leased-back by the Company and are accounted for as a finance lease. As of September 30, 2020 and September 30, 2019, finance lease obligations associated with these sale leaseback agreements were $5 million and $13 million, respectively.

Business Combinations

Business Combinations	12 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Business Combinations and Strategic Partnerships and Investments	Business Combinations and Strategic Partnerships and Investments Business Combination On March 9, 2018 (the "Acquisition Date"), the Company acquired Intellisist, Inc. ("Spoken"), a United States-based private technology company, which provides cloud-based Contact Center as a Service ("CCaaS") solutions and customer experience management and automation applications. The total purchase price was $172 million, consisting of $157 million in cash, $14 million in contingent consideration and a $1 million settlement of Spoken’s net payable to the Company, which mainly related to services provided by the Company to Spoken under a co-development partnership prior to the acquisition. Upon the achievement of three specified performance targets ("Earn-outs"), the Company was required to pay up to $16 million of contingent consideration to Spoken's former owners and employees and up to $4 million in discretionary earn-out bonuses ("Earn-out Bonuses") to Spoken employees who had contributed to the achievement of the Earn-outs. The fair value of the Earn-outs at the Acquisition Date was $14 million, which was calculated using a probability-weighted discounted cash flow model and was remeasured to fair value at each subsequent reporting period. The Earn-out Bonuses, which were intended to incentivize continuing employees to assist in achieving the Earn-outs, were excluded from the acquisition consideration and were recognized as compensation expense in the Company's Consolidated Financial Statements ratably over the estimated Earn-out periods. During fiscal 2020 and 2019, the Company paid $5 million and $11 million for Earn-outs, respectively. During both fiscal 2020 and 2019, the Company also paid $2 million for Earn-out Bonuses. As of September 30, 2020, all potential Earn-outs and Earn-out Bonuses were fully settled. In connection with this acquisition, the Company recorded goodwill of $117 million, which was assigned to the Products & Solutions segment, identifiable intangible assets with a fair value of $64 million and other net liabilities of $9 million. The goodwill recognized was attributable primarily to the potential that the Spoken technology, cloud platform and assembled workforce would accelerate the Company's growth in cloud-based solutions. The goodwill is not deductible for tax purposes. The acquired intangible assets of $64 million included technology and patents of $56 million with a weighted average useful life of 4.9 years, $5 million of in-process research and development ("IPR&D") activities, which are considered indefinite lived until projects are completed or abandoned, and customer relationships of $3 million with a weighted average useful life of 7.5 years. During fiscal 2019, $3 million of the acquired IPR&D activities were completed and are being amortized over a weighted average useful life of 4.2 years and $2 million were abandoned and written off (see Note 8, "Intangible Assets, net"). During the period from December 16, 2017 through September 30, 2018, the Company recorded $3 million of acquisition-related costs, which included investment banking, legal and other third-party costs, and $7 million of compensation expense resulting from the accelerated vesting of certain unvested Spoken stock option awards because post-combination service requirements were eliminated. The acquisition-related costs and the compensation expense were recorded in Selling, general and administrative expense in the Consolidated Statements of Operations. Strategic Partnership On October 3, 2019, the Company entered into certain agreements that establish the framework for the Company's strategic partnership with RingCentral, a leading provider of global enterprise cloud communications, collaboration and contact center ("CC") solutions, to accelerate the Company's transition to the cloud. Through this partnership, the Company introduced Avaya Cloud Office by RingCentral ("Avaya Cloud Office" or "ACO"), a new global unified communications as a service ("UCaaS") solution. Avaya Cloud Office expands the Company's portfolio to offer a full suite of Unified Communications and Collaboration ("UCC"), CC, UCaaS and contact center as a service solutions to its global customer base. ACO combines RingCentral's leading UCaaS platform with Avaya technology, services and migration capabilities to create a highly differentiated UCaaS offering. The transaction closed on October 31, 2019 and ACO was launched on March 31, 2020. As part of the strategic partnership, the Company and RingCentral also entered into an agreement governing the terms of the commercial arrangement between the parties (the "Framework Agreement"). Under the Framework Agreement, the parties entered into a Super Master Agent Agreement, pursuant to which Avaya acts as an agent to Avaya's channel partners with respect to the sale of ACO and make direct sales of ACO. RingCentral pays a fee to Avaya, including for the benefit of its channel partners, for each such sale. In addition, for each unit of ACO sold during the term of the Framework Agreement, RingCentral pays Avaya certain fees. Among other things, the Framework Agreement requires Avaya to (subject to certain exceptions) market and sell ACO as its exclusive UCaaS solution (as defined in the Framework Agreement). The Framework Agreement has a multiyear term and can be terminated early by either party in the event (i) the other party fails to cure a material breach or (ii) the other party undergoes a change in control. In accordance with the Framework Agreement, RingCentral paid Avaya $375 million, predominantly for future fees, as well as for certain licensing rights. The $375 million payment consisted of $361 million in shares of RingCentral common stock and $14 million in cash. During fiscal 2020, the Company sold all of its shares of RingCentral common stock and recognized a gain of $59 million within Other income (expense), net in the Consolidated Statements of Operation s . In connection with the strategic partnership, the Company and RingCentral entered into an investment agreement, whereby RingCentral purchased 125,000 shares of the Company's Series A 3% Convertible Preferred Stock, par value $0.01 per share (the "Series A Preferred Stock"), for an aggregate purchase price of $125 million. See Note 17, "Capital Stock" for additional information on the Series A Preferred Stock. Strategic Investment On May 20, 2019, the Company made a $10 million investment in a UCaaS provider delivering public sector Federal Risk and Authorization Management Program ("FedRAMP") security requirements (the “Investee”) through the acquisition of a 3-year convertible note (“Promissory Note”). The Investee offers hosted, cloud-based Voice over Internet Protocol infrastructure services and a FedRAMP authorized hosting platform. The Promissory Note has a principal amount of $10 million, bears interest at a rate of 8% per annum and has a maturity date of May 20, 2022. Under the terms of the Promissory Note, the Company may, at its sole discretion, convert its interest in the Promissory Note into newly issued Class D units of the Investee representing no less than 27.3% of the Investee's fully diluted capitalization at the time of the conversion. On or after the Promissory Note’s maturity date, the Company will have the option, at its sole discretion, to demand payment from the Investee for the unpaid principal and accrued interest on the Promissory Note. In conjunction with the purchase of the Promissory Note, the Company entered into a separate agreement with the Investee and its equity holders which provides the Company with an option to purchase from such equity holders any or all of the outstanding LLC units of the Investee for prices specified in the relevant agreement. The option is exercisable upon the earlier of December 31, 2021 or the Investee reaching specified milestones. The option does not currently convey power to the Company as it is not currently exercisable and requires significant economic outlay. The Promissory Note was classified as an available-for-sale security as of September 30, 2019 with a carrying value and fair value of $10 million and was recorded within Other Assets in the Consolidated Balance Sheets. Although the Company maintains a variable interest in the Investee, it is not the primary beneficiary as it does not direct the activities that most significantly impact the economic performance of the Investee through the rights maintained with the Promissory Note or separate agreement.

Goodwill_2

Goodwill	12 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill, netThe changes in the carrying amount of goodwill by segment for the periods indicated were as follows: (In millions) Products & Solutions Services Total Balance as of September 30, 2018 (Successor) Cost $ 1,283 $ 1,481 $ 2,764 Accumulated impairment charges — — — 1,283 1,481 2,764 Impairment charges 657 — 657 Foreign currency fluctuations (1) (1) (2) Other — (2) (2) Balance as of September 30, 2019 (Successor) Cost 1,282 1,478 2,760 Accumulated impairment charges (657) — (657) 625 1,478 2,103 Impairment charges (624) — (624) Foreign currency fluctuations (1) 1 — Other — (1) (1) Balance as of September 30, 2020 (Successor) Cost 1,281 1,478 2,759 Accumulated impairment charges (1,281) — (1,281) $ — $ 1,478 $ 1,478 Fiscal 2020 (Successor) During the first quarter of fiscal 2020, the Company changed its reporting units to align with changes in its organizational structure, mainly resulting from the previously disclosed strategic review process which concluded in October 2019. As a result, on October 1, 2019, the Company consolidated its UCC and CC reporting units into a Products & Solutions reporting unit and consolidated its Global Support Services ("GSS"), Avaya Professional Services ("APS") and Enterprise Cloud and Managed Services ("ECMS") reporting units into a Services reporting unit. As a result of these changes, the Company's reporting units are the same as its operating segments which are described in Note 19, "Operating Segments." Due to the consolidation of reporting units, the Company performed an interim goodwill impairment assessment immediately before and after the consolidation on October 1, 2019 by estimating and comparing the fair value of each reporting unit to its carrying value. The Company determined that the carrying amounts of each of the Company's reporting units did not exceed their estimated fair values and therefore no impairment existed as of October 1, 2019. During the second quarter of fiscal 2020, the Company concluded that a triggering event occurred for both of its reporting units due to (i) the impact of the COVID-19 pandemic on the macroeconomic environment which led to revisions to the Company's long-term forecast during the second quarter of fiscal 2020 and (ii) the sustained decrease in the Company's stock price since the advent of the pandemic which was caused by the resulting volatility in the financial markets. As a result, the Company performed an interim quantitative goodwill impairment test as of March 31, 2020 to compare the fair values of its reporting units to their respective carrying amounts, including the goodwill allocated to each reporting unit. The results of the Company's interim goodwill impairment test as of March 31, 2020 indicated that the estimated fair value of the Company's Services reporting unit exceeded its carrying amount. The carrying amount of the Company's Products & Solutions reporting unit exceeded its estimated fair value primarily due to a reduction in the Company's long-term forecast to reflect increased risk from higher market uncertainty and the accelerated reduction of product sales related to the Company's historical on-premise perpetual licenses. The Company anticipates a continued shift and acceleration of customers upgrading and acquiring new technology innovation through the utilization of the Company's subscription offering, which is included in the Services reporting unit. As a result, the Company recorded a goodwill impairment charge of $624 million in fiscal 2020 to write down the full carrying amount of the Products & Solutions goodwill in the Impairment charges line item in the Consolidated Statements of Operations. The Company performed its annual goodwill impairment test as of July 1, 2020. As permitted under ASC 350, t he Company performed a qualitative goodwill impairment assessment to determine whether it was more likely than not that the fair value of its Services reporting unit was less than its carrying amount, including goodwill. After assessing all relevant qualitative factors, the Company determined that it was more likely than not that the fair value of the reporting unit exceeded its carrying amount and a quantitative goodwill impairment test was not necessary. The Company's long-term forecast includes significant estimates and assumptions, including management's estimate of the potential impact of the COVID-19 pandemic on the Company's operating results. Due to the uncertainty surrounding the impact of the COVID-19 pandemic on the macroeconomic environment and, more specifically, on the Company's future operating results, it is reasonably possible that the pandemic could have a more adverse impact than what is currently contemplated by the Company's long-term forecast. The Company determined that no events occurred or circumstances changed during the three months ended September 30, 2020 that would indicate that it is more likely than not that its goodwill was impaired. To the extent that business conditions deteriorate or if changes in key assumptions and estimates differ significantly from management's expectations, it may be necessary to record additional impairment charges in the future. Fiscal 2019 (Successor) During the third quarter of fiscal 2019, the Company concluded that triggering events occurred for all of its reporting units due to a sustained decrease in the Company's stock price and lower than planned financial results which led to revisions to the Company's long-term forecast during the third quarter of fiscal 2019. As a result, the Company performed an interim quantitative goodwill impairment test as of June 30, 2019 to compare the fair values of its reporting units to their respective carrying values, including the goodwill allocated to each reporting unit. The results of the Company’s interim goodwill impairment test as of June 30, 2019 indicated that the estimated fair values of the Company’s UCC, GSS, APS and ECMS reporting units were greater than their carrying amounts, however, the carrying amount of the Company’s CC reporting unit within the Products & Solutions segment exceeded its estimated fair value primarily due to a reduction in the Company's long-term forecast. As a result, the Company recorded a goodwill impairment charge of $657 million in fiscal 2019 in the Impairment charges line item in the Consolidated Statements of Operations representing the amount by which the carrying value of the CC reporting unit exceeded its fair value. The Company performed its annual goodwill impairment test on July 1, 2019 and determined that the carrying amounts of each of the Company's reporting units did not exceed their estimated fair values and therefore no impairment existed. The Period from December 16, 2017 through September 30, 2018 (Successor) and the Period from October 1, 2017 through December 15, 2017 (Predecessor)

Intangible Assets

Intangible Assets	12 Months Ended
	Sep. 30, 2020
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Intangible Assets	Intangible Assets, netThe Company's intangible assets consist of the following for the periods indicated: (In millions) Customer Trademarks Total Balance as of September 30, 2020 Finite-lived intangible assets: Cost $ 961 $ 2,153 $ 42 $ 3,156 Accumulated amortization (482) (433) (18) (933) Finite-lived intangible assets, net 479 1,720 24 2,223 Indefinite-lived intangible assets: Cost — — 333 333 Accumulated impairment — — — — Indefinite-lived intangible assets, net — — 333 $ 333 Intangible assets, net $ 479 $ 1,720 $ 357 $ 2,556 Balance as of September 30, 2019 Finite-lived intangible assets: Cost $ 960 $ 2,154 $ 42 $ 3,156 Accumulated amortization (308) (279) (11) (598) Finite-lived intangible assets, net 652 1,875 31 2,558 Indefinite-lived intangible assets: Cost $ 2 $ — $ 333 $ 335 Accumulated impairment (2) — — (2) Indefinite-lived intangible assets, net $ — $ — $ 333 $ 333 Intangible assets, net $ 652 $ 1,875 $ 364 $ 2,891 Amortization expense for fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor) was $335 million, $336 million, $262 million and $13 million, respectively. Future amortization expense of intangible assets as of September 30, 2020 for the fiscal years ending September 30, is as follows: (In millions) 2021 $ 331 2022 304 2023 287 2024 185 2025 and thereafter 1,116 Total $ 2,223 Fiscal 2020 (Successor) As a result of the triggering event described in Note 7, "Goodwill, net," the Company performed a recoverability test on all of its finite-lived asset groups and indefinite-lived intangible assets as of March 31, 2020 before proceeding to the goodwill impairment review. As of March 31, 2020, the Company's interim quantitative impairment test for the finite-lived asset groups and indefinite-lived intangible asset, the Avaya Trade Name, indicated no impairment existed. As of July 1, 2020, the Company performed its annual impairment test of the Avaya Trade Name and determined that its estimated fair value exceeded its carrying amount and no impairment existed. The Company determined that no events occurred or circumstances changed during the three months ended September 30, 2020 that would indicate that its finite-lived intangible assets may not be recoverable or that it is more likely than not that its indefinite-lived intangible assets were impaired. To the extent that business conditions deteriorate or if changes in key assumptions and estimates differ significantly from management's expectations, it may be necessary to record impairment charges in the future. Fiscal 2019 (Successor) During fiscal 2019, the Company elected to abandon an in-process research and development project that no longer aligned with the Company's technology roadmap. As a result, the Company recorded an impairment charge of $2 million to write down the full carrying amount of the project within the Impairment charges line item in the Consolidated Statements of Operations. As a result of the triggering events described in Note 7, "Goodwill, net," the Company performed a recoverability test on all of its finite-lived asset groups as of June 30, 2019 before proceeding to the goodwill impairment review and concluded that no impairment charge was necessary. The Company also performed an interim quantitative impairment test for the Avaya Trade Name as of June 30, 2019 and determined that its estimated fair value exceeded its carrying value and no impairment existed. At July 1, 2019, the Company performed its annual impairment test of the Avaya Trade Name and determined that its estimated fair value exceeded its carrying amount and no impairment existed. 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.

Supplementary Financial Informa

Supplementary Financial Information	12 Months Ended
	Sep. 30, 2020
Supplementary Financial Information [Abstract]
Supplementary Financial Information	Supplementary Financial Information Consolidated Statements of Operations Information The following table presents a summary of depreciation and amortization and Other income (expense), net for the periods indicated: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 DEPRECIATION AND AMORTIZATION Amortization of intangible assets (included in Costs and Operating expenses) $ 335 $ 336 $ 262 $ 13 Depreciation and amortization of property, plant and equipment and internal use software (included in Costs and Operating expenses) 88 107 122 18 Total depreciation and amortization $ 423 $ 443 $ 384 $ 31 OTHER INCOME (EXPENSE), NET Interest income $ 6 $ 14 $ 5 $ 2 Foreign currency (losses) gains, net (16) (8) 28 — Gain on investments in equity and debt securities, net 49 — — — Other pension and post-retirement benefit credits (costs), net 22 7 13 (8) Change in fair value of Emergence Date Warrants (3) 29 (17) — Sublease income 5 — — — Income from transition services agreement, net — — 5 3 Other, net — (1) 1 1 Total other income (expense), net $ 63 $ 41 $ 35 $ (2) The gain on investments in equity and debt securities, net for fiscal 2020 includes a gain on shares of RingCentral common stock of $59 million and is partially offset by a $10 million impairment of debt securities owned by the Company, which is further described in Note 6, "Business Combinations and Strategic Partnerships and Investments." The Foreign currency gains, net for the period from December 16, 2017 through September 30, 2018 was principally due to the strengthening of the U.S. dollar compared to certain foreign exchange rates on U.S. dollar denominated receivables maintained in non-U.S. locations, mainly Argentina, India and Mexico. As of July 1, 2018, we concluded that Argentina represents a hyperinflationary economy as its projected three-year cumulative inflation rate exceeds 100%. As a result, we changed the local functional currency for our Argentinian operations from the Argentine Peso to the U.S. Dollar effective July 1, 2018 and remeasured the financial statements for those operations to the U.S. Dollar as of July 1, 2018 in accordance with ASC 830 "Foreign Currency Matters." Although the remeasurement on July 1, 2018 did not have an impact on our Consolidated Financial Statements, foreign exchange transaction gains and losses recognized on or after July 1, 2018 are based on our Argentina operation's new U.S. dollar functional currency. A summary of Reorganization items, net for the periods indicated is presented in the following table: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 REORGANIZATION ITEMS, NET Net gain on settlement of Liabilities subject to compromise $ — $ — $ — $ 1,778 Net gain on fresh start adjustments — — — 1,697 Bankruptcy-related professional fees — — — (56) Other items, net — — — (3) Reorganization items, net $ — $ — $ — $ 3,416 Cash payments for reorganization items $ — $ — $ 1 $ 2,524 Costs directly attributable to the implementation of the Plan of Reorganization were reported as Reorganization items, net. The cash payments for reorganization items for the period from October 1, 2017 through December 15, 2017 included $2,468 million of claims paid related to Liabilities subject to compromise and $56 million for bankruptcy-related professional fees, including emergence and success fees paid on the Emergence Date. Consolidated Balance Sheet Information Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 VALUATION AND QUALIFYING ACCOUNTS Allowance for Doubtful Accounts Receivable: Balance at beginning of period $ 4 $ 2 $ — $ 13 Increase in expense 5 2 2 1 Reductions (2) — — (1) Impact of fresh start accounting — — — (13) Balance at end of period $ 7 $ 4 $ 2 $ — Deferred Tax Asset Valuation Allowance: Balance at beginning of period $ 928 $ 919 $ 836 $ 2,152 Increase (decrease) in expense 58 43 105 (452) Additions (reductions) 67 (34) (22) (393) Impact of fresh start accounting — — — (471) Balance at end of period $ 1,053 $ 928 $ 919 $ 836 As of September 30, (In millions) 2020 2019 PROPERTY, PLANT AND EQUIPMENT, NET Leasehold improvements $ 97 $ 101 Machinery and equipment 265 221 Assets under construction 30 30 Internal use software 188 154 Total property, plant and equipment 580 506 Less: Accumulated depreciation and amortization (312) (251) Property, plant and equipment, net $ 268 $ 255 As of September 30, 2020, Machinery and equipment and Accumulated depreciation and amortization include $27 million and $(15) million, respectively, for assets acquired under finance leases. As of September 30, 2019, Machinery and equipment and Accumulated depreciation and amortization include $17 million and $(12) million, respectively, for assets acquired under finance leases. Supplemental Cash Flow Information Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 OTHER PAYMENTS Interest payments $ 197 $ 206 $ 149 $ 15 Income tax payments 101 56 22 7 NON-CASH INVESTING ACTIVITIES Acquisition of equipment under finance leases $ 9 $ 3 $ 2 $ — (Decrease) increase in Accounts payable, Other current liabilities and Other liabilities for Capital expenditures (4) 6 1 — During fiscal 2020, the Company made payments for operating lease liabilities of $66 million and recorded non-cash additions for operating lease right-of-use assets of $35 million. The following table presents a reconciliation of cash, cash equivalents, and restricted cash that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows for the periods presented: Successor Predecessor As of September 30, (In millions) 2020 2019 2018 December 15, 2017 CASH, CASH EQUIVALENTS, AND RESTRICTED CASH Cash and cash equivalents $ 727 $ 752 $ 700 $ 366 Restricted cash included in other current assets — — — 65 Restricted cash included in other assets 4 4 4 4 Total cash, cash equivalents, and restricted cash $ 731 $ 756 $ 704 $ 435 As of December 15, 2017 (Predecessor), restricted cash in other current assets consisted primarily of funds held for bankruptcy-related professional fees.

Business Restructuring Reserves

Business Restructuring Reserves and Programs	12 Months Ended
	Sep. 30, 2020
Restructuring Reserve [Abstract]
Business Restructuring Reserves and Programs	Business Restructuring Reserves and ProgramsThe following table summarizes the restructuring charges by activity for the periods presented: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 Employee separation costs $ 6 $ 19 $ 70 $ 13 Facility exit costs 24 3 11 $ 1 Total restructuring charges $ 30 $ 22 $ 81 $ 14 The restructuring charges include changes in estimates for increases and decreases in costs or changes in the timing of payments related to the restructuring programs of prior fiscal years. The Company's employee separation costs generally consist of severance charges which include, but are not limited to, termination payments, pension fund payments, and health care and unemployment insurance costs to be paid to, or on behalf of, the affected employees. Facility exit costs primarily consist of lease obligation charges for exited facilities, including the impact of accelerated lease expense for right-of-use assets and accelerated depreciation expense for leasehold improvements with reductions in their estimated useful lives due to exited facilities. The Company does not allocate restructuring reserves to its operating segments. As a result of the adoption of ASC 842 on October 1, 2019, the Company no longer records facility-related restructuring charges within the Business restructuring reserves on the Consolidated Balance Sheets. As a result, the Company recorded a one-time reclassification of $5 million for certain facility-related lease obligations from Business restructuring reserves to Operating lease right-of-use assets upon adoption of ASC 842. The following table summarizes the activity for employee separation costs recognized under the Company's restructuring programs for the periods presented: (In millions) Fiscal 2020 Restructuring Program (2) Fiscal 2019 Restructuring Program (3) Fiscal 2018 Restructuring Program (3) Fiscal 2008 through 2017 Restructuring Programs (3) Total Accrual balance as of September 30, 2017 (Predecessor) $ — $ — $ — $ 55 $ 55 Cash payments — — (3) (4) (7) Restructuring charges — — 12 1 13 Adjustments (1) — — — 4 4 Impact of foreign currency fluctuations — — — — — Accrual balance as of December 15, 2017 (Predecessor) $ — $ — $ 9 $ 56 $ 65 Accrual balance as of December 16, 2017 (Successor) $ — $ — $ 9 $ 56 $ 65 Cash payments — — (23) (17) (40) Restructuring charges — — 70 — 70 Adjustments (1) — — — — — Impact of foreign currency fluctuations — — (2) (1) (3) Accrual balance as of September 30, 2018 (Successor) — — 54 38 92 Cash payments — (8) (19) (16) (43) Restructuring charges — 20 — — 20 Adjustments (1) — — (2) 1 (1) Impact of foreign currency fluctuations — (1) (2) (1) (4) Accrual balance as of September 30, 2019 (Successor) — 11 31 22 64 Cash payments (1) (5) (11) (9) (26) Restructuring charges 8 — — — 8 Adjustments (1) — — (1) (1) (2) Impact of foreign currency fluctuations 1 1 2 1 5 Accrual balance as of September 30, 2020 (Successor) $ 8 $ 7 $ 21 $ 13 $ 49 (1) Includes changes in estimates for increases and decreases in costs related to the Company's restructuring programs, which are recorded in Restructuring charges, net in the Consolidated Statements of Operations in the period of the adjustment. (2) Payments related to the fiscal 2020 restructuring program are expected to be completed in fiscal 2027. (3) Payments related to the fiscal 2019, 2018 and 2008 through 2017 restructuring programs are expected to be completed in fiscal 2026.

Financing Arrangement

Financing Arrangement	12 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Financing Arrangements	Financing Arrangements The following table reflects principal amounts of debt and debt net of discounts and issuance costs for the periods presented: September 30, 2020 September 30, 2019 (In millions) Principal amount Net of discounts and issuance costs Principal amount Net of discounts and issuance costs Term Loan Credit Agreement due December 15, 2024 and 2027 $ 1,643 $ 1,611 $ 2,874 $ 2,846 Senior 6.125% Notes due September 15, 2028 1,000 984 — — Convertible 2.25% Senior Notes due June 15, 2023 350 291 350 273 Total debt $ 2,993 2,886 $ 3,224 3,119 Debt maturing within one year — (29) Long-term debt, net of current portion $ 2,886 $ 3,090 Term Loan and ABL Credit Agreements On December 15, 2017, Avaya Inc. entered into (i) the Term Loan Credit Agreement among Avaya Inc., as borrower, Avaya Holdings, the lending institutions from time to time party thereto, and Goldman Sachs Bank USA, as administrative agent and collateral agent, which provided a $2,925 million term loan facility maturing on December 15, 2024 (the "Term Loan Credit Agreement") and (ii) the ABL Credit Agreement maturing on December 15, 2022, among Avaya Inc., as borrower, Avaya Holdings, the several other borrowers party thereto, the several lenders from time to time party thereto, and Citibank, N.A., as administrative agent and collateral agent, which provided a revolving credit facility consisting of a U.S. tranche and a foreign tranche allowing for borrowings of up to an aggregate principal amount of $300 million from time to time, subject to borrowing base availability (the "ABL Credit Agreement" and, together with the Term Loan Credit Agreement, the "Credit Agreements"). On June 18, 2018, the Company amended the Term Loan Credit Agreement ("Amendment No.1") to reduce interest rates and to reduce the London Inter-bank Offered Rate ("LIBOR") floor that existed under the original agreement from 1.00% to 0.00%. After Amendment No.1, the Term Loan Credit Agreement (a) in the case of alternative base rate ("ABR") Loans, bears interest at a rate per annum equal to 3.25% plus the highest of (i) the Federal Funds Rate plus 0.50%, (ii) the U.S. prime rate as publicly announced in the Wall Street Journal and (iii) the LIBOR Rate for an interest period of one month and (b) in the case of LIBOR Loans, bears interest at a rate per annum equal to 4.25% plus the applicable LIBOR rate, subject to a 0.00% floor. Prior to Amendment No.1, the Term Loan Credit Agreement, in the case of ABR Loans, bore interest at a rate per annum equal to 3.75% plus the highest of (i) the Federal Funds Rate plus 0.50%, (ii) the U.S. prime rate as publicly announced in the Wall Street Journal and (iii) the LIBOR Rate for an interest period of one month and in the case of LIBOR Loans, bore interest at a rate per annum equal to 4.75% plus the applicable LIBOR rate, subject to a 1.00% floor. As a result of Amendment No.1, outstanding loan balances under the original Term Loan Credit Agreement were paid in full and new debt was issued for the same outstanding principal amount. Amendment No.1 was accounted for as a loan modification under ASC 470, "Debt" ("ASC 470"). On September 25, 2020, the Company closed a private offering of $1,000 million aggregate principal amount of its Senior 6.125% First Lien Notes due September 15, 2028 (the “Senior Notes,” which are described in more detail below). On September 25, 2020, the Company also amended the Term Loan Credit Agreement (“Amendment No. 2”), pursuant to which the maturity of $800 million in principal amount of the first lien term loans outstanding under the Term Loan Credit Agreement was extended from December 2024 to December 2027. Amendment No. 2 also made certain other changes to the Term Loan Credit Agreement, including with respect to the change of control provisions. Concurrently with Amendment No. 2, the Company also used the net proceeds from the issuance of its Senior Notes after debt issuance costs to repurchase and prepay $981 million of certain first lien term loans under the Term Loan Credit Agreement whose maturity was not extended pursuant to Amendment No. 2. The Company evaluated the issuance of the Senior Notes, the $981 million principal prepayment on the Term Loan Credit Agreement and Amendment No. 2 (collectively the “Debt Transactions”) under the loan modification and extinguishment guidance within ASC 470. The Debt Transactions were accounted for as a partial modification, partial extinguishment and new debt issuance at the syndicated lender level. Based on the application of the loan modification and extinguishment guidance within ASC 470 to the Debt Transactions, the Company capitalized $32 million of new debt issuance costs and underwriting discounts as a reduction to Long-term debt on the Consolidated Balance Sheets; recorded $9 million of new debt issuance costs and underwriting discounts within Interest Expense in the Consolidated Statements of Operations; and wrote-off a portion of the original underwriting discount on the Term Loan Credit Agreement of $5 million to Interest expense. During fiscal 2020, the Company made total principal prepayments on its Term Loan Credit Agreement of $1,231 million, including the $981 million prepayment on September 25, 2020 described above. Due to the prepayments, there are no amounts due within one year on the Term Loan Credit Agreement and the balance has been classified as non-current as of September 30, 2020. For fiscal 2020, the Company recognized interest expense of $161 million related to the Term Loan Credit Agreement, including the expenses associated with the Debt Transactions described above and the amortization of the underwriting discount. For fiscal 2019 and the period from December 16, 2017 through September 30, 2018, the Company recognized interest expense of $200 million and $154 million, respectively, related to the Term Loan Credit Agreement, including the amortization of the underwriting discount. On September 25, 2020, the Company also amended the ABL Credit Agreement to, among other things, extend its maturity to September 25, 2025, subject to customary adjustments to the extent certain indebtedness matures prior to such date. The total commitments under the ABL Credit Agreement were also reduced from $300 million to $200 million, subject to borrowing base availability. As a result of the amendment, the Company capitalized $2 million of issuance costs within Other assets on the Consolidated Balance Sheets in accordance with ASC 470. Prior to the effectiveness of the September 25, 2020 amendment, the ABL Credit Agreement bore interest at the following rates: 1. In the case of Base Rate Loans denominated in U.S. dollars, at a rate per annum equal to 0.75% (subject to a 0.25% step-up or step-down based on availability) plus the highest of (i) the Federal Funds Rate plus 0.50%, (ii) the U.S. prime rate as publicly announced by Citibank, N.A. and (iii) the LIBOR Rate for an interest period of one month; 2. In the case of LIBOR Rate Loans denominated in U.S. dollars, at a rate per annum equal to 1.75% (subject to a 0.25% step-up or step-down based on availability) plus the applicable LIBOR Rate; 3. In the case of Canadian Prime Rate Loans denominated in Canadian dollars, at a rate per annum equal to 0.75% (subject to a 0.25% step-up or step-down based on availability) plus the highest of (i) the "Base Rate" as publicly announced by Citibank, N.A., Canadian branch and (ii) the rate of interest per annum equal to the average rate applicable to Canadian Dollar Bankers Rate ("CDOR Rate") for an interest period of 30 days; 4. In the case of CDOR Rate Loans denominated in Canadian dollars, at a rate per annum equal to 1.75% (subject to a 0.25% step-up or step-down based on availability) plus the applicable CDOR Rate; 5. In the case of LIBOR Rate Loans denominated in Sterling, at a rate per annum equal to 1.75% (subject to a 0.25% step-up or step-down based on availability) plus the applicable LIBOR Rate; 6. In the case of Euro Interbank Offered Rate ("EURIBOR Rate") Loans denominated in Euro, at a rate per annum equal to 1.75% (subject to a 0.25% step-up or step-down based on availability) plus the applicable LIBOR Rate; and 7. In the case of Overnight LIBOR Rate Loans, at a rate per annum equal to 1.75% (subject to a 0.25% step-up or step-down based on availability) plus the applicable Overnight LIBOR Rate. Subsequent to the effectiveness of the September 25, 2020 amendment, the ABL Credit Agreement bears interest at the following rates: 1. In the case of Base Rate Loans denominated in U.S. dollars, at a rate per annum equal to 1.00% (subject to a 0.25% step-up or step-down based on availability) plus the highest of (i) the Federal Funds Rate plus 0.50%, (ii) the U.S. prime rate as publicly announced by Citibank, N.A. and (iii) the LIBOR Rate for an interest period of one month; 2. In the case of LIBOR Rate Loans denominated in U.S. dollars, at a rate per annum equal to 2.00% (subject to a 0.25% step-up or step-down based on availability) plus the applicable LIBOR Rate; 3. In the case of Canadian Prime Rate Loans denominated in Canadian dollars, at a rate per annum equal to 1.00% (subject to a 0.25% step-up or step-down based on availability) plus the highest of (i) the "Base Rate" as publicly announced by Citibank, N.A., Canadian branch and (ii) the rate of interest per annum equal to the average rate applicable to Canadian Dollar Bankers Rate ("CDOR Rate") for an interest period of 30 days; 4. In the case of CDOR Rate Loans denominated in Canadian dollars, at a rate per annum equal to 2.00% (subject to a 0.25% step-up or step-down based on availability) plus the applicable CDOR Rate; 5. In the case of LIBOR Rate Loans denominated in Sterling, at a rate per annum equal to 2.00% (subject to a 0.25% step-up or step-down based on availability) plus the applicable LIBOR Rate; 6. In the case of Euro Interbank Offered Rate ("EURIBOR Rate") Loans denominated in Euro, at a rate per annum equal to 2.00% (subject to a 0.25% step-up or step-down based on availability) plus the applicable LIBOR Rate; and 7. In the case of Overnight LIBOR Rate Loans, at a rate per annum equal to 2.00% (subject to a 0.25% step-up or step-down based on availability) plus the applicable Overnight LIBOR Rate. The Credit Agreements limit, among other things, the ability of Avaya Inc. and certain of its subsidiaries to (i) incur indebtedness, (ii) incur liens, (iii) dispose of assets, (iv) make investments, (v) make dividends, or conduct redemptions and repurchases of capital stock, (vi) prepay junior indebtedness or amend junior indebtedness documents, (vii) enter into restricted agreements, (viii) enter into transactions with affiliates and (ix) modify the terms of any of their organizational documents. The Credit Agreements also contain customary representations, warranties and events of default. The Term Loan Credit Agreement does not contain any financial covenants. The ABL Credit Agreement does not contain any financial covenants other than a requirement to maintain a minimum fixed charge coverage ratio of 1:1 that becomes applicable only in the event that the net borrowing availability under the ABL Credit Agreement is less than the greater of $16 million and 10% of the lesser of the total borrowing base and the ABL commitments (commonly known as the "line cap"). Under the terms of the ABL Credit Agreement, the Company can issue letters of credit up to $150 million. At September 30, 2020, the Company had issued and outstanding letters of credit and guarantees of $41 million under the ABL Credit Agreement. As of September 30, 2020, the Company had no borrowings outstanding under the ABL Credit Agreement. The aggregate additional principal amount that may be borrowed under the ABL Credit Agreement, based on the borrowing base less $41 million of outstanding letters of credit and guarantees, was $153 million at September 30, 2020. For fiscal 2020, fiscal 2019 and the period from December 16, 2017 through September 30, 2018, the Company recognized interest expense of $1 million related to the ABL Credit Agreement, primarily resulting from the unused commitment fee. Senior Notes As noted above, on September 25, 2020, the Company’s Senior Notes were issued pursuant to an indenture, among the Company, the Company's subsidiaries that are guarantors of the Senior Notes and party thereto (the “Guarantors”) and Wilmington Trust, National Association, as trustee and notes collateral agent. Interest is payable on the Senior Notes at a rate of 6.125% per annum on March 15 and September 15 of each year, commencing on March 15, 2021 until their maturity date of September 15, 2028. The Senior Notes are guaranteed on a senior secured basis by Avaya and each of the Company’s other wholly-owned domestic subsidiaries that guarantee the Company’s term loan credit facility (the “Term Loan Facility”) under the Company’s Term Loan Credit Agreement and asset-based revolving credit facility (the “ABL Facility”) under the Company’s ABL Credit Agreement. The Senior Notes and related guarantees are secured on a first lien basis by substantially all assets of the Company and the Guarantors (other than any excluded collateral as defined in the indenture or ABL Priority Collateral (as defined below)) which assets also secure the Company’s and each Guarantor’s obligations under the Term Loan Facility ratably on a pari passu basis, subject to permitted liens. The Senior Notes and related guarantees are also secured on a second-lien basis ratably on a pari passu basis with the Term Loan Facility, subject to permitted liens, by certain of the assets of the Company and the Guarantors that secure obligations under the ABL Facility on a first-lien basis (the “ABL Priority Collateral”). The Senior Notes contain covenants that, among other things, limit the Company’s ability and the ability of its restricted subsidiaries to: incur or guarantee additional indebtedness or issue disqualified stock or certain preferred stock; pay dividends and make other distributions or repurchase stock; make certain investments; create or incur liens; sell assets; enter into restrictions affecting the ability of restricted subsidiaries to make distributions, loans or advances or transfer assets to the Company or the Guarantors; enter into certain transactions with the Company’s affiliates; designate restricted subsidiaries as unrestricted subsidiaries; and merge, consolidate or transfer or sell all or substantially all of the Company’s or the Guarantors’ assets. These covenants are subject to a number of important exceptions and qualifications. The Company may redeem the Senior Notes at any time, in whole or in part, at any time prior to maturity. The redemption price for Senior Notes that are redeemed before September 15, 2023 will be equal to 100% of the principal amount of the Senior Notes to be redeemed, plus accrued and unpaid interest, if any, plus an applicable make-whole premium. The redemption price for Senior Notes that are redeemed on or after September 15, 2023 will be equal to redemption prices as set forth in the indenture, together with any accrued and unpaid interest. In addition, the Company may redeem up to 40% of the Senior Notes using the proceeds of certain equity offerings completed before September 15, 2023. During fiscal 2020, the Company recognized interest expense of $1 million related to the Senior Notes, including the amortization of debt issuance costs. Convertible Notes On June 11, 2018, the Company issued its 2.25% Convertible Notes with an aggregate principal amount of $350 million (including notes issued in connection with the underwriters’ exercise in full of an over-allotment option of $50 million), which mature on June 15, 2023 (the "Convertible Notes"). The Convertible Notes were issued under an indenture (the "Indenture"), by and between the Company and the Bank of New York Mellon Trust Company N.A., as Trustee. The Company received net proceeds from the offering of $314 million after giving effect to debt issuance costs, including the underwriting discount, the net cash used to purchase a bond hedge and the proceeds from the issuance of warrants, which are discussed below. The Convertible Notes accrue interest at a rate of 2.25% per annum, payable semi-annually on June 15 and December 15 of each year. On or after March 15, 2023, and until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert the Convertible Notes at the holders' option. Holders may convert the Convertible Notes, at the holders' option, prior to March 15, 2023 only under the following circumstances: • during any calendar quarter, if the last reported sale price of the Company's common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; • during the five business day period after any five consecutive trading day period (the "Measurement Period") in which the trading price per $1,000 principal amount of the Convertible Notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sales price of the Company's common stock and the conversion rate on each such trading day; or • upon the occurrence of specified corporate events. The Convertible Notes are convertible at an initial rate of 36.0295 shares per $1,000 of principal (equivalent to an initial conversion price of $27.76 per share of the Company's common stock). The conversion rate is subject to customary adjustments for certain events as described in the Indenture. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its common stock, or a combination of cash and shares of its common stock, at the Company's election. It is the Company’s current intent to settle conversions of the Convertible Notes through combination settlement, which involves repayment of the principal portion in cash and any excess of the conversion value over the principal amount in shares of its common stock. The Company may not redeem the Convertible Notes prior to their maturity date, and no sinking fund is provided for them. If the Company undergoes a fundamental change, as described in the Indenture, subject to certain conditions, holders may require the Company to repurchase for cash all or any portion of the Convertible Notes. The fundamental change repurchase price is equal to 100% of the principal amount of the Convertible Notes to be repurchased, plus accrued and unpaid interest up to, but excluding, the fundamental change repurchase date. If holders elect to convert the Convertible Notes in connection with a make-whole fundamental change, as described in the Indenture, the Company will, to the extent provided in the Indenture, increase the conversion rate applicable to the Convertible Notes. The Indenture does not contain any financial or operating covenants or restrictions on the payment of dividends, the incurrence of indebtedness, or the issuance or repurchase of securities by the Company or any of its subsidiaries. The Indenture contains customary events of default with respect to the Convertible Notes. In accounting for the issuance of the Convertible Notes, the Company separated the Convertible Notes into liability and equity components. The Company allocated $258 million of the Convertible Notes to the liability component, and $92 million to the equity component. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component, which represents the conversion option and does not meet the criteria for separate accounting as a derivative as it is indexed to the Company's own stock, was determined by deducting the fair value of the liability component from the par value of the Convertible Notes. The excess of the principal amount of the liability component over its carrying amount represents a debt discount, which was recorded as a direct deduction from the related debt liability in the Consolidated Balance Sheets and is amortized to interest expense over the term of the Convertible Notes using the effective interest method. The equity component is included in Additional paid-in capital in the Consolidated Balance Sheets and will not be remeasured as long as it continues to meet the conditions for equity classification. The Company incurred issuance costs of $10 million related to the Convertible Notes. Issuance costs were allocated to the liability and equity components based on the same proportion used to allocate the proceeds. Issuance costs attributable to the liability component of $7 million are amortized to interest expense over the term of the Convertible Notes, and issuance costs attributable to the equity component of $3 million are included along with the equity component in stockholders' equity. For fiscal 2020, fiscal 2019 and the period from December 16, 2017 through September 30, 2018, the Company recognized interest expense of $26 million, $25 million, and $7 million related to the Convertible Notes, which includes $18 million, $17 million and $4 million of amortization of the underwriting discount and issuance costs, respectively. The net carrying amount of the Convertible Notes for the periods indicated was as follows: As of September 30, (In millions) 2020 2019 Principal $ 350 $ 350 Less: Unamortized debt discount (55) (72) Unamortized issuance costs (4) (5) Net carrying amount $ 291 $ 273 Bond Hedge and Call Spread Warrants In connection with the issuance of the Convertible Notes, the Company also entered into privately negotiated transactions to purchase hedge instruments ("Bond Hedge"), covering 12.6 million shares of its common stock at a cost of $84 million. The Bond Hedge is subject to anti-dilution provisions substantially similar to those of the Convertible Notes, has a strike price of $27.76 per share, is exercisable by the Company upon any conversion of the Convertible Notes, and expires on June 15, 2023. The cost of the Bond Hedge was recorded as a reduction of Additional paid-in capital in the accompanying Consolidated Balance Sheets. The Company also sold warrants for the purchase of up to 12.6 million shares of its common stock for aggregate proceeds of $58 million ("Call Spread Warrants"). The Call Spread Warrants have a strike price of $37.3625 per share and are subject to customary anti-dilution provisions. The Call Spread Warrants will expire in ratable portions on a series of expiration dates commencing on September 15, 2023. The proceeds from the issuance of the Call Spread Warrants were recorded as an increase to Additional paid-in capital. The Bond Hedge and Call Spread Warrants are intended to reduce the potential dilution with respect to the Company’s common stock and/or reduce the Company’s exposure to potential cash payments that the Company may be required to make upon conversion of the Convertible Notes by, in effect, increasing the conversion price, from the Company’s economic standpoint, to $37.3625 per share. However, the Call Spread Warrants could have a dilutive effect with respect to the Company's common stock or, if the Company so elects, obligate the Company to make cash payments to the extent that the market price of common stock exceeds $37.3625 per share on any date upon which the Call Spread Warrants are exercised. Debt Maturity The stated annual maturity of total debt for the fiscal years ended September 30, consist of: (In millions) 2021 $ — 2022 — 2023 350 2024 — 2025 and thereafter 2,643 Total $ 2,993 The weighted average contractual interest rate of the Company’s outstanding debt was 6.5% and 6.3%, as of September 30, 2020 and 2019, respectively. The effective interest rate for the Term Loan Credit Agreement as of September 30, 2020 and 2019 was not materially different than its contractual interest rate including adjustments related to interest rate swap agreements designated as highly effective cash flow hedges. The effective interest rate for the Senior Notes as of September 30, 2020 was not materially different than its contractual interest rate. The effective interest rate for the Convertible Notes as of both September 30, 2020 and 2019 was 9.2% reflecting the separation of the conversion feature in equity. The effective interest rates include interest on the debt and amortization of discounts and issuance costs. Effective January 19, 2017, the Company ceased recording interest expense on outstanding pre-petition debt classified as liabilities subject to compromise. Contractual interest expense represented amounts due under the contractual terms of outstanding debt, including debt subject to compromise. For the period from October 1, 2017 through December 15, 2017 (Predecessor) contractual interest expense of $94 million was not recorded as interest expense, as it was not an allowed claim under the Bankruptcy Filing. As of September 30, 2020, the Company was not in default under any of its debt agreements.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	12 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities The Company accounts for derivative financial instruments in accordance with FASB ASC Topic 815 "Derivatives and Hedging," ("ASC 815") and does not enter into derivatives for trading or speculative purposes. Interest Rate Contracts The Company, from time-to-time, enters into interest rate swap contracts as a hedge against changes in interest rates on its outstanding variable rate loans. On May 16, 2018, the Company entered into interest rate swap agreements with six counterparties, which fix a portion of the variable interest due under its Term Loan Credit Agreement (the "Original Swap Agreements"). Under the terms of the Original Swap Agreements, which mature on December 15, 2022, the Company pays a fixed rate of 2.935% and receives a variable rate of interest based on one-month LIBOR. Through September 23, 2020, the total $1,800 million notional amount of the Original Swap Agreements were designated as cash flow hedges and deemed highly effective as defined under ASC 815. On September 23, 2020, the Company entered into an interest rate swap agreement for a notional amount of $257 million (the “Offsetting Swap Agreement”). Under the terms of the Offsetting Swap Agreement, which matures on December 15, 2022, the Company pays a variable rate of interest based on one-month LIBOR and receives a fixed rate of 0.1745%. The Company entered into the Offsetting Swap Agreement to maintain a net notional amount less than the amount of the Company’s variable rate loans outstanding. The Offsetting Swap Agreement was not designated for hedge accounting treatment. On September 23, 2020, Original Swap Agreements with a notional amount of $257 million were also de-designated from hedge accounting treatment. As of September 30, 2020, Original Swap Agreements with a notional amount of $1,543 million continue to be designated as cash flow hedges and deemed highly effective as defined under ASC 815. On July 1, 2020, the Company entered into interest rate swap agreements with four counterparties, which fix a portion of the variable interest due on its Term Loan Credit Agreement (the "New Swap Agreements") from December 15, 2022 (the maturity date of the Original Swap Agreements) through December 15, 2024. Under the terms of the New Swap Agreements, the Company will pay a fixed rate of 0.7047% and receive a variable rate of interest based on one-month LIBOR. The total notional amount of the New Swap Agreements is $1,400 million. Since their execution, the New Swap Agreements have been designated as cash flow hedges and deemed highly effective as defined by ASC 815. The Company records changes in the fair value of interest rate swap agreements designated as cash flow hedges initially within Accumulated other comprehensive loss in the Consolidated Balance Sheets. As interest expense is recognized on the Term Loan Credit Agreement, the corresponding deferred gain or loss on the cash flow hedge is reclassified from Accumulated other comprehensive loss to Interest expense in the Consolidated Statements of Operations. The Company records changes in the fair value of interest rate swap agreements not designated for hedge accounting within Interest expense. On September 23, 2020, the Company froze a $15 million deferred loss within Accumulated other comprehensive loss for the de-designated Original Swap Agreements, which will be reclassified to Interest expense over the term of the Original Swap Agreements. Based on the amount in Accumulated other comprehensive loss at September 30, 2020, approximately $50 million would be reclassified to interest expense in the next twelve months. It is management's intention that the net notional amount of interest rate swap agreements be less than the variable rate loans outstanding during the life of the derivatives. Foreign Currency Forward Contracts The Company, from time to time, utilizes foreign currency forward contracts primarily to hedge fluctuations associated with certain monetary assets and liabilities including receivables, payables and certain intercompany balances. These foreign currency forward contracts are not designated for hedge accounting treatment. As a result, changes in the fair value of these contracts are recorded as a component of Other income (expense), net to offset the change in the value of the hedged assets and liabilities. As of September 30, 2020, the Company maintained open foreign currency forward contracts with a total notional value of $375 million, primarily hedging the British Pound Sterling, Euro, Chinese Renminbi and Indian Rupee. As of September 30, 2019, the Company maintained open foreign currency forward contracts with a total notional value of $400 million, primarily hedging the British Pound Sterling, Indian Rupee, Chinese Renminbi, Czech Koruna, Mexican Peso and Australian Dollar. Emergence Date Warrants In accordance with the Plan of Reorganization, the Company issued warrants to purchase 5,645,200 shares of Company common stock under a warrant agreement to the holders of the Predecessor second lien obligations extinguished pursuant to the Plan of Reorganization (the "Emergence Date Warrants"). Each Emergence Date Warrant has an exercise price of $25.55 per share and expires December 15, 2022. The Emergence Date Warrants contain certain derivative features that require them to be classified as a liability and for changes in the fair value of the liability to be recognized in earnings each reporting period. On November 14, 2018, the Company's Board of Directors approved a warrant repurchase program, authorizing the Company to repurchase up to $15 million worth of the Emergence Date Warrants. None of the Emergence Date Warrants have been exercised or repurchased as of September 30, 2020. The fair value of the Emergence Date Warrants was determined using a probability weighted Black-Scholes option pricing model. This model requires certain input assumptions including risk-free interest rates, volatility, expected life and dividend rates. Selection of these inputs involves significant judgment. The fair value of the Emergence Date Warrants as of September 30, 2020 and 2019 was determined using the input assumptions summarized below: As of September 30, 2020 2019 Expected volatility 68.53 % 56.89 % Risk-free interest rates 0.14 % 1.55 % Contractual remaining life (in years) 2.21 3.21 Price per share of common stock $15.20 $10.23 In determining the fair value of the Emergence Date Warrants, the dividend yield was assumed to be zero as the Company does not anticipate paying dividends throughout the term of the warrants. Financial Statement Information Related to Derivative Instruments The following table summarizes the fair value of the Company's derivatives on a gross basis, including accrued interest, segregated between those that are designated as hedging instruments and those that are not designated as hedging instruments: September 30, 2020 September 30, 2019 (In millions) Balance Sheet Caption Asset Liability Asset Liability Derivatives Designated as Hedging Instruments: Interest rate contracts Other current liabilities — 43 — 23 Interest rate contracts Other liabilities — 58 — 58 — 101 — 81 Derivatives Not Designated as Hedging Instruments: Interest rate contracts Other current liabilities — 7 — — Interest rate contracts Other liabilities — 9 — — Foreign exchange contracts Other current assets 1 — 1 — Foreign exchange contracts Other current liabilities — 2 — — Emergence Date Warrants Other liabilities — 8 — 5 1 26 1 5 Total derivative fair value $ 1 $ 127 $ 1 $ 86 The following table provides information regarding the location and amount of pre-tax (losses) gains for interest rate swaps designated as cash flow hedges: Fiscal years ended September 30, Period from December 16, 2017 2020 2019 (In millions) Interest Expense Other Comprehensive (Loss) Income Interest Expense Other Comprehensive (Loss) Income Interest Expense Other Comprehensive (Loss) Income Financial Statement Line Item in which Cash Flow Hedges are Recorded $ (226) $ (72) $ (237) $ (191) $ (169) $ 18 Impact of cash flow hedging relationships: Loss recognized in AOCI - on interest rate swaps — (69) — (87) — (9) Interest expense reclassified from AOCI (35) 35 (10) 10 (6) 6 The following table provides information regarding the pre-tax (losses) gains for derivatives not designated as hedging instruments on the Consolidated Statements of Operations: Fiscal years ended September 30, Period from December 16, 2017 (In millions) Location of Derivative Pre-tax Gain (Loss) 2020 2019 Emergence Date Warrants Other income (expense), net (3) $ 29 $ (17) Foreign exchange contracts Other income (expense), net (1) (5) — The Company records its derivatives on a gross basis in the Consolidated Balance Sheets. The Company has master netting agreements with several of its financial institution counterparties. The following table provides information on the Company's derivative positions as if those subject to master netting arrangements were presented on a net basis, allowing for the right to offset by counterparty per the master netting agreements: September 30, 2020 September 30, 2019 (In millions) Asset Liability Asset Liability Gross amounts recognized in the Consolidated Balance Sheet $ 1 $ 127 $ 1 $ 86 Gross amount subject to offset in master netting arrangements not offset in the Consolidated Balance Sheet (1) (1) (1) (1) Net amounts $ — $ 126 $ — $ 85

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Pursuant to the accounting guidance for fair value measurements, fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and it considers assumptions that market participants would use when pricing the asset or liability. Considerable judgment was required in developing certain of the estimates of fair value including the consideration of the recent COVID-19 pandemic that has caused significant volatility in U.S. and international markets, and accordingly, the estimates presented herein are not necessarily indicative of the amounts that the Company could realize in a current market exchange. Fair Value Hierarchy The accounting guidance for fair value measurements also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The inputs are prioritized into three levels that may be used to measure fair value: Level 1: Inputs that reflect quoted prices for identical assets or liabilities in active markets that are observable. Level 2: Inputs that reflect quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or model-derived valuations in which significant inputs are observable or can be derived principally from, or corroborated by, observable market data. Level 3: Inputs that are unobservable to the extent that observable inputs are not available for the asset or liability at the measurement date. Assets and Liabilities Measured at Fair Value on a Recurring Basis Assets and liabilities measured at fair value on a recurring basis as of September 30, 2020 and 2019 were as follows: September 30, 2020 September 30, 2019 Fair Value Measurements Using Fair Value Measurements Using (In millions) Total Level 2 Level 3 Total Level 2 Level 3 Assets: Investments in debt securities $ — $ — $ — $ — $ 10 $ — $ — $ 10 Foreign exchange contracts 1 — 1 — 1 — 1 — Total assets $ 1 $ — $ 1 $ — $ 11 $ — $ 1 $ 10 Liabilities: Interest rate contracts $ 117 $ — $ 117 $ — $ 81 $ — $ 81 $ — Spoken acquisition Earn-outs — — — — 5 — — 5 Foreign exchange contracts 2 — 2 — — — — — Emergence Date Warrants 8 — — 8 5 — — 5 Total liabilities $ 127 $ — $ 119 $ 8 $ 91 $ — $ 81 $ 10 Investments in debt securities The investments in debt securities were valued using a discounted cash flow model which includes various unobservable inputs including cash flow projections, long-term growth rates, discount rates and market comparable companies. The investments in debt securities were recorded in Other assets in the Consolidated Balance Sheets. Interest rate and foreign exchange contracts Interest rate and foreign exchange contracts classified as Level 2 assets and liabilities are not actively traded and are valued using pricing models that use observable inputs. Spoken acquisition Earn-outs The Spoken acquisition Earn-outs classified as Level 3 liabilities were measured using a probability-weighted discounted cash flow model. Significant unobservable inputs, which included probability of the achievement of the Earn out targets and discount rate assumption, reflected the assumptions market participants would use in valuing these liabilities. The Earn-outs were recorded in Other current liabilities in the Consolidated Balance Sheets. Emergence Date Warrants Emergence Date Warrants classified as Level 3 liabilities are valued using the Black-Scholes option pricing model. During fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), there were no transfers between Level 1 and Level 2, or into and out of Level 3. The following table summarizes the activity for the Company's Level 3 assets and liabilities measured at fair value on a recurring basis: (In millions) Emergence Date Warrants Spoken acquisition earn-outs Investments in debt securities Balance as of September 30, 2019 $ 5 $ 5 $ 10 Impairment (1) — — (10) Changes in fair value (2) 3 — — Settlement — (5) — Balance as of September 30, 2020 $ 8 $ — $ — (1) During fiscal 2020, the Company recorded an other-than-temporary impairment charge for a $10 million credit loss on its investments in debt securities. See Note 6, "Business Combinations and Strategic Partnerships and Investments," for additional information. (2) Changes in fair value of the Emergence Date Warrants are included in Other income (expense), net. Fair Value of Financial Instruments The estimated fair values of the Company’s Term Loan Credit Agreement, Senior Notes and Convertible Notes at September 30, 2020 and 2019 were as follows: September 30, 2020 September 30, 2019 (In millions) Principal amount Fair value Principal amount Fair value Term Loan Credit Agreement due December 15, 2024 and 2027 $ 1,643 $ 1,624 $ 2,874 $ 2,739 Senior 6.125% Notes due September 15, 2028 1,000 1,022 — — Convertible 2.25% Senior Notes due June 15, 2023 350 331 350 298 Total $ 2,993 $ 2,977 $ 3,224 $ 3,037 The estimated fair value of the Company's Term Loan Credit Agreement and Senior Notes was determined using Level 2 inputs based on a market approach utilizing market-clearing data on the valuation date in addition to bid/ask prices. The estimated fair value of the Convertible Notes was determined based on the quoted price of the Convertible Notes in an inactive market on the last trading day of the reporting period and has been classified as Level 2. The fair values of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses, to the extent the underlying liability will be settled in cash, approximate their carrying values because of the short-term nature of these instruments.

Income Taxes

Income Taxes	12 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes During the year ended September 30, 2018, under the Plan of Reorganization, a substantial amount of the Company’s debt was extinguished. Absent an exception, a debtor recognizes the cancellation of indebtedness income ("CODI") upon discharge of its outstanding indebtedness for an amount of consideration that is less than its adjusted issue price. The Company's U.S. federal net operating loss ("NOL") and tax credits not utilized during the taxable year ended September 30, 2018 were eliminated in the year ended September 30, 2018 due to the recognition of CODI. Prior to December 15, 2017, a full valuation allowance was established in any jurisdiction that had a net deferred tax asset. A portion of the U.S. valuation allowance in the amount of $787 million was reversed as part of the reorganization adjustments as it was previously established against (i) the NOL and tax credits that as of December 15, 2017 were estimated to be eliminated as a result of the CODI rules and (ii) other deferred tax assets that were previously established for liabilities that were discharged in the Plan or Reorganization and eliminated as part of the reorganization adjustments. The valuation allowance in the amount of $47 million was reversed in certain non-U.S. jurisdictions as part of the reorganization adjustments as management concluded it was more likely than not that the related deferred tax assets will be realized. The remaining U.S. valuation allowance in the amount of $460 million was reversed as part of the fresh start adjustments because management concluded it was more likely than not that the deferred tax assets will be realized primarily due to future sources of taxable income that will be generated by the reversal of deferred tax liabilities established as a result of fresh start. During the fourth quarter of fiscal 2018, the Company centralized the management and ownership of certain intellectual property in a U.S. limited partnership. This action resulted in the utilization and recognition of previously unrecognized NOLs, the reversal of deferred tax liabilities established as part of fresh start accounting and the recognition of a deferred tax asset, cumulatively in the amount of $366 million. On December 22, 2017, the Tax Cuts and Jobs Act (the "Act") was signed into law. The Act lowered the U.S. federal corporate tax rate from 35% to 21% effective January 1, 2018. Corporations with a fiscal year-end that is not a calendar year but included January 1, 2018 were subject to a blended tax rate based on the number of days in the fiscal year before and after January 1, 2018. The Company has a September 30 th tax year-end and therefore the U.S. federal tax rate for the fiscal year ending September 30, 2018 was 24.5%. The SEC issued Staff Accounting Bulletin No. 118 ("SAB 118") on December 22, 2017, which provided guidance to registrants on the accounting for tax related impacts under the Act. The guidance provides a measurement period of up to one year after the enactment date for companies to complete the tax accounting implications of the Act. As a fiscal year-end tax filer, the Company was subject to various provisions under the Act for the period from December 16, 2017 through September 30, 2018, including the change to the U.S. federal statutory tax rate and the mandatory deemed repatriation of unremitted foreign earnings. In fiscal 2018, the Company recorded adjustments related to the Act, including a revaluation of its deferred taxes. The amount of the reduction to the net deferred tax liability as a result of the Act was $245 million and had been recorded as an income tax benefit in the period from December 16, 2017 through September 30, 2018. During fiscal 2019, various U.S. tax provisions that were introduced or updated as part of the Act became effective for the Company, including provisions that result in the current U.S. taxation of certain income earned by the Company’s foreign subsidiaries. The FASB has published guidance (Topic 740, No. 5) regarding how to account for the Global Intangible Low-Taxed Income ("GILTI") provisions included in the Act. The guidance states that a company may make a policy decision with respect to the accounting for taxes related to GILTI and whether deferred taxes should be established. The Company has generated income that is taxed as GILTI in fiscal 2020 and 2019. The Company has determined that it will account for any taxes associated with GILTI as a period cost. The Company previously established a deferred tax liability for non-U.S. withholding taxes to be incurred upon the remittance of foreign earnings which was $17 million as of September 30, 2020. The Company has a taxable outside basis difference of $83 million as of September 30, 2020 which was permanently reinvested. The Company estimates the unrecorded deferred tax liability on the outside basis difference to be $20 million. The (provision for) benefit from income taxes is comprised of U.S. federal, state and foreign income taxes. The following table presents the U.S. and foreign components of (loss) income before income taxes and the (provision for) benefit from income taxes for the periods indicated: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 (LOSS) INCOME BEFORE INCOME TAXES: U.S. $ (639) $ (510) $ (165) $ 3,353 Foreign 21 (159) (94) 83 (Loss) income before income taxes $ (618) $ (669) $ (259) $ 3,436 (PROVISION FOR) BENEFIT FROM INCOME TAXES: CURRENT Federal $ (58) $ (20) $ — $ — State and local (10) (7) 4 — Foreign (23) (29) (40) (4) (91) (56) (36) (4) DEFERRED Federal 30 47 530 (453) State and local 3 10 34 (19) Foreign (4) (3) 18 17 29 54 582 (455) (Provision for) benefit from income taxes $ (62) $ (2) $ 546 $ (459) Deferred income taxes are provided for the effects of temporary differences between the amounts of assets and liabilities recognized for financial reporting purposes and the amounts recognized for income tax purposes. Significant components of the Company's deferred tax assets and liabilities as of the periods indicated were as follows: As of September 30, (In millions) 2020 2019 DEFERRED INCOME TAX ASSETS: Benefit obligations $ 218 $ 225 Net operating losses/credit carryforwards 981 918 Property, plant and equipment 8 15 Other/accrued liabilities 13 — Valuation allowance (1,053) (928) Gross deferred income tax assets 167 230 DEFERRED INCOME TAX LIABILITIES: Goodwill and intangible assets (174) (213) Other/accrued liabilities — (54) Gross deferred income tax liabilities (174) (267) Net deferred income tax liabilities $ (7) $ (37) A reconciliation of the Company’s (loss) income before income taxes at the U.S. federal statutory rate to the (provision for) benefit from income taxes is as follows: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 Income tax benefit (provision) computed at the U.S. Federal statutory rate $ 130 $ 140 $ 64 $ (1,203) State and local income taxes, net of federal income tax effect 2 11 (12) 10 Tax differentials on foreign earnings — (11) (12) 182 Loss on foreign subsidiaries 28 29 43 — Taxes on unremitted foreign earnings and profits (8) (4) 4 7 Non-deductible portion of goodwill (125) (123) — — Non-deductible reorganization items — — — (11) Adjustment to deferred taxes (14) 16 4 (1) Audit settlements and accruals 6 5 (48) (6) Credits and other taxes (2) 4 (5) (1) Impact of Tax Cuts and Jobs Act (3) 1 245 — NOL recognition / intellectual property — — 366 — Warrants (1) 6 (4) — Debt refinancing — — (8) — Non-deductible impact of fresh start accounting — — — (555) Non-taxable cancellation of debt income — — — 313 Attribute reduction — — — (452) Rate changes (3) (19) (3) — U.S. tax on foreign source income — — (10) (2) Valuation allowance (58) (43) (85) 1,199 Other differences—net (14) (14) 7 61 (Provision for) benefit from income taxes $ (62) $ (2) $ 546 $ (459) In fiscal 2020 and 2019, the Company recognized goodwill impairment charges of $624 million and $657 million, respectively. See Note 7, "Goodwill, net" for further discussion. In assessing the realization of deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company considered the scheduled reversal of deferred tax assets and liabilities, projected future taxable income and certain tax planning strategies in assessing the realization of its deferred tax assets. Based on this assessment, the Company determined that it is more likely than not that the deferred tax assets in certain significant jurisdictions, including the U.S., Ireland, Germany, Luxembourg and France, will not be realized to the extent they exceed the scheduled reversal of deferred tax liabilities. During fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), the Company's valuation allowance increased (decreased) by $125 million, $9 million, $82 million and $(1,316) million, respectively, primarily due to valuation allowances established for additional NOLs and the tax effects related to other comprehensive income. At September 30, 2020, the valuation allowance of $1,053 million is comprised of $76 million, $341 million, $589 million and $47 million related to the U.S., Germany, Luxembourg, and other foreign subsidiaries, respectively. The recognition of valuation allowances will continue to adversely affect the Company's effective income tax rate. As of September 30, 2020, the Company had tax-effected NOLs and credits of $1,006 million, comprised of $17 million for U.S. state and local taxes and $989 million for foreign taxes, including $260 million and $679 million in Germany and Luxembourg, respectively. The U.S. state NOLs expire through fiscal 2039, with the majority expiring in excess of 10 years. The majority of foreign NOLs have no expiration. As of September 30, 2020, there were $140 million of unrecognized tax benefits ("UTBs") associated with uncertain tax positions and an additional $25 million of accrued interest and penalties related to these amounts. The Company estimates $89 million of UTBs would affect the effective tax rate if recognized. The reduction in the balance during fiscal 2020 is primarily related to the expiration of relevant statute of limitations. At this time, the Company is unable to make a reasonably reliable estimate of the timing of payments in connection with these tax liabilities. The Company’s policy is to include interest and penalties related to its uncertain tax positions within the (provision for) benefit from income taxes. Included in the (provision for) benefit from income taxes in fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor) was a net interest (expense) benefit of $(3) million, $(4) million, $0 million and $1 million, respectively. The Company files corporate income tax returns with the federal government in the U.S. and with multiple U.S. state and local jurisdictions and foreign tax jurisdictions. In the ordinary course of business these income tax returns will be examined by the tax authorities. Various foreign income tax returns, such as Brazil, Italy, Germany, India, Ireland, Israel, and Netherlands are under examination by taxing authorities for tax years ranging from 2001 through 2019. It is reasonably possible that the total amount of UTB will decrease by an estimated $8 million in the next 12 months as a result of these examinations and by an estimated $5 million as a result of the expiration of the statute of limitations. The following table summarizes the activity for the Company's gross UTB balance: (In millions) Gross UTB balance at September 30, 2017 (Predecessor) 268 Additions based on tax positions relating to the period 4 Gross UTB balance at December 15, 2017 (Predecessor) $ 272 Gross UTB balance at December 16, 2017 (Successor) $ 272 Additions based on tax positions relating to the period 57 Changes based on tax positions relating to prior periods (143) Statute of limitations expirations (12) Gross UTB balance at September 30, 2018 (Successor) 174 Additions based on tax positions relating to the period 10 Changes based on tax positions relating to prior periods (32) Statute of limitations expirations (5) Gross UTB balance at September 30, 2019 (Successor) $ 147 Additions based on tax positions relating to the period 4 Changes based on tax positions relating to prior periods (1) Settlements (2) Statute of limitations expirations (8) Gross UTB Balance at September 30, 2020 (Successor) $ 140

Benefit Obligations

Benefit Obligations	12 Months Ended
	Sep. 30, 2020
Retirement Benefits [Abstract]
Benefit Obligations	Benefit Obligations Pension, Post-retirement and Postemployment Benefits The Company sponsors non-contributory defined benefit pension plans covering a portion of its U.S. employees and retirees, and post-retirement benefit plans covering a portion of its U.S. employees and retirees that include healthcare benefits and life insurance coverage. Certain non-U.S. operations have various retirement benefit programs covering substantially all of their employees. Some of these programs are considered to be defined benefit pension plans for accounting purposes. The Company froze benefit accruals and additional participation in the pension and post-retirement benefit plans for its U.S. management employees effective December 31, 2003. In June 2019, the Company announced a change in medical benefits under the post-retirement medical plan for represented retirees effective January 1, 2020, to replace medical coverage through the Company's group plan for represented retirees who are retired as of April 30, 2019 and their eligible dependents, with medical coverage through the private and public insurance marketplace. As a result of the plan amendment, the Company recognized a $7 million reduction in the accumulated benefit obligation with an offset to Accumulated other comprehensive loss in the Consolidated Balance Sheet during fiscal 2019. On December 15, 2017, the Avaya Inc. Pension Plan for Salaried Employees ("APPSE"), a qualified pension plan, was settled with the Pension Benefit Guaranty Corporation ("PBGC"). At that time, the Company and the PBGC executed a termination and trusteeship agreement to terminate the APPSE and to appoint the PBGC as the statutory trustee of the plan. The Company paid settlement consideration to the PBGC consisting of $340 million in cash and 6.1 million shares of Successor Company common stock (fair value of $92 million). With this payment, any accrued but unpaid minimum funding contributions due were deemed to have been paid in full. As a result of the plan termination on December 15, 2017, the Company's projected benefit obligation and pension trust assets were reduced by $2,192 million and $1,573 million, respectively. Including the settlement consideration and $703 million of Accumulated other comprehensive loss recorded in the Consolidated Balance Sheets, a settlement loss of $516 million was recorded in Reorganization items, net in the Consolidated Statements of Operations for the period from October 1, 2017 through December 15, 2017 (Predecessor). On December 15, 2017, the unfunded Avaya Supplemental Pension Plan ("ASPP"), a non-qualified excess benefit plan, was also terminated and settled. Benefit liabilities for ASPP participants were included as allowed claims in the general unsecured recovery pool. Settlement consideration of $17 million in the form of allowed claims payable to ASPP participants was estimated based upon claims data as of the Emergence Date as amounts due to individual general unsecured creditors had not been finalized and paid. As a result of the termination, the Company's projected benefit obligation was reduced by $88 million. Including the settlement consideration and $18 million of Accumulated other comprehensive loss recorded in the Consolidated Balance Sheet, a settlement gain of $53 million was recorded in Reorganization items, net in the Consolidated Statements of Operations for the period from October 1, 2017 through December 15, 2017 (Predecessor). Remeasurement as a result of fresh start accounting increased the Avaya Pension Plan ("APP") and other post-retirement benefit plan obligations by $3 million on December 15, 2017. Effective September 9, 2019, the Company and the Communications Workers of America ("CWA") and the International Brotherhood of Electrical Workers ("IBEW"), agreed to extend the 2009 Collective Bargaining Agreement ("CBA") until June 19, 2021. The contract extensions did not affect the Company’s obligation for pension and post-retirement benefits available to U.S. employees of the Company who are represented by the CWA or IBEW ("represented employees"). Most post-retirement medical benefits are not pre-funded. Consequently, the Company makes payments directly to the claims administrator as retiree medical benefit claims are disbursed. These payments are funded by the Company up to the maximum contribution amounts specified in the plan documents and contract with the CWA and IBEW, and contributions from the participants, if required. Payments for retiree medical and dental benefits were $10 million, $12 million, $7 million and $2 million for fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), respectively, which were net of reimbursements received of $3 million in both fiscal 2020 and 2019 related to payments in prior periods. The Company estimates it will make payments for retiree medical and dental benefits totaling $11 million during fiscal 2021. A reconciliation of the changes in the benefit obligations and fair value of assets of the defined benefit pension and post-retirement plans, the funded status of the plans and the amounts recognized in the Consolidated Balance Sheets are provided in the tables below: Fiscal years ended September 30, (In millions) 2020 2019 Pension Benefits - U.S. Change in benefit obligation Projected benefit obligation at beginning of period $ 1,134 $ 1,050 Service cost 4 3 Interest cost 29 40 Actuarial loss 55 131 Benefits paid (77) (90) Projected benefit obligation at end of period $ 1,145 $ 1,134 Change in plan assets Fair value of plan assets at beginning of period $ 915 $ 881 Actual return on plan assets 79 97 Employer contributions 10 27 Benefits paid (77) (90) Fair value of plan assets at end of period $ 927 $ 915 Underfunded status at end of period $ (218) $ (219) Amount recognized in the Consolidated Balance Sheets consists of: Accrued benefit liability, noncurrent $ (218) $ (219) Net amount recognized $ (218) $ (219) Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of: Net actuarial loss 110 79 Net amount recognized $ 110 $ 79 Weighted average assumptions used to determine benefit obligations Discount rate 2.50 % 3.09 % Rate of compensation increase 3.00 % 3.00 % Fiscal years ended September 30, (In millions) 2020 2019 Pension Benefits - Non-U.S. Change in benefit obligation Projected benefit obligation at beginning of period $ 573 $ 536 Service cost 7 6 Interest cost 5 10 Actuarial (gain) loss (34) 76 Benefits paid (21) (22) Foreign currency exchange rate changes 42 (32) Curtailments, settlements and other 1 (1) Projected benefit obligation at end of period $ 573 $ 573 Change in plan assets Fair value of plan assets at beginning of period $ 15 $ 15 Actual return on plan assets — 1 Employer contributions 22 23 Benefits paid (21) (22) Foreign currency exchange rate changes 2 (1) Settlements — (1) Fair value of plan assets at end of period $ 18 $ 15 Underfunded status at end of period $ (555) $ (558) Amount recognized in the Consolidated Balance Sheets consists of: Noncurrent assets $ 1 $ 1 Accrued benefit liability, current (25) (19) Accrued benefit liability, noncurrent (531) (540) Net amount recognized $ (555) $ (558) Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of: Net actuarial loss $ 22 $ 55 Net amount recognized $ 22 $ 55 Weighted average assumptions used to determine benefit obligations Discount rate 0.86 % 0.87 % Rate of compensation increase 2.60 % 2.59 % Fiscal years ended September 30, (In millions) 2020 2019 Post-retirement Benefits - U.S. Change in benefit obligation Benefit obligation at beginning of period $ 404 $ 368 Service cost 1 1 Interest cost 11 14 Actuarial loss 30 44 Benefits paid (15) (16) Plan amendments — (7) Projected benefit obligation at end of period $ 431 $ 404 Change in plan assets Fair value of plan assets at beginning of period $ 191 $ 178 Actual return on plan assets 20 17 Employer contributions 10 12 Benefits paid (15) (16) Fair value of plan assets at end of period $ 206 $ 191 Underfunded status at end of period $ (225) $ (213) Amount recognized in the Consolidated Balance Sheets consists of: Accrued benefit liability, current $ (10) $ (13) Accrued benefit liability, noncurrent (215) (200) Net amount recognized $ (225) $ (213) Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of: Net prior service credit $ (6) $ (7) Net actuarial loss $ 23 $ 3 Net amount recognized $ 17 $ (4) Weighted average assumptions used to determine benefit obligations Discount rate 2.69 % 3.17 % Rate of compensation increase 3.00 % 3.00 % Effective September 30, 2020, to reflect its best estimate of future mortality for its salaried post-retirement benefit plans, the Company started using the White-Collar PRI-2012 Private Retirement Plans Mortality Tables . For the U.S. pension and represented post-retirement benefit plans, the Company continued to use the PRI-2012 Private Retirement Plans Mortality Tables . The Company also updated its mortality rate assumptions to use the projected mortality improvement scale, Mortality Projection-2020 , as published by the Society of Actuaries. As of September 30, 2020, the changes in mortality rate assumptions had the effect of decreasing the projected U.S. pension and post-retirement obligations by $10 million and $5 million, respectively. The following table provides the accumulated benefit obligation for all defined benefit pension plans and information for pension plans with an accumulated benefit obligation in excess of plan assets: Pension Benefits - U.S. Pension Benefits - Non-U.S. (In millions) September 30, 2020 September 30, 2019 September 30, 2020 September 30, 2019 Accumulated benefit obligation for all plans $ 1,145 $ 1,134 $ 555 $ 555 Plans with accumulated benefit obligation in excess of plan assets Projected benefit obligation $ 1,145 $ 1,134 $ 567 $ 568 Accumulated benefit obligation $ 1,145 $ 1,134 $ 549 $ 550 Fair value of plan assets $ 927 $ 915 $ 12 $ 9 Estimated future benefits expected to be paid in each of the next five fiscal years, and in aggregate for the five fiscal years thereafter, are presented below: Pension Benefits Post-retirement (In millions) U.S. Non-U.S. 2021 $ 74 $ 24 $ 17 2022 73 24 18 2023 73 23 19 2024 72 23 19 2025 71 24 20 2026 - 2030 338 136 107 Total $ 701 $ 254 $ 200 The components of the pension and post-retirement net periodic benefit (credit) cost for the periods indicated are provided in the table below: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 Pension Benefits - U.S. Components of net periodic benefit (credit) cost Service cost $ 4 $ 3 $ 3 $ 1 Interest cost 29 40 28 22 Expected return on plan assets (55) (60) (51) (38) Amortization of actuarial loss — — — 20 Net periodic benefit (credit) cost $ (22) $ (17) $ (20) $ 5 Weighted average assumptions used to determine net periodic benefit cost Discount rate 2.84 % 3.94 % 3.29 % 3.19 % Expected return on plan assets 6.40 % 7.00 % 7.65 % 7.75 % Rate of compensation increase 3.00 % 4.00 % 4.00 % 4.00 % Pension Benefits - Non-U.S. Components of net periodic benefit cost Service cost $ 7 $ 6 $ 5 $ 2 Interest cost 5 10 7 3 Expected return on plan assets (1) (1) — (1) Amortization of actuarial loss — — — 2 Net periodic benefit cost $ 11 $ 15 $ 12 $ 6 Weighted average assumptions used to determine net periodic benefit cost Discount rate 0.87 % 1.92 % 1.92 % 1.22 % Expected return on plan assets 3.72 % 3.67 % 3.68 % 1.82 % Rate of compensation increase 2.59 % 2.58 % 3.62 % 3.45 % Post-retirement Benefits - U.S. Components of net periodic benefit cost Service cost $ 1 $ 1 $ 1 $ — Interest cost 11 14 11 3 Expected return on plan assets (10) (9) (8) (2) Amortization of prior service credit (1) — — (3) Amortization of actuarial (gain) loss — (1) — 2 Net periodic benefit cost $ 1 $ 5 $ 4 $ — Weighted average assumptions used to determine net periodic benefit cost Discount rate 2.18 % 4.02 % 3.39 % 3.37 % Expected return on plan assets 5.50 % 5.50 % 5.50 % 5.90 % Rate of compensation increase 3.00 % 4.00 % 4.00 % 4.00 % The service components of net periodic benefit (credit) cost were recorded similar to compensation expense, while all other components were recorded in Other income (expense), net. The Company's general funding policy with respect to its U.S. qualified pension plans is to contribute amounts at least sufficient to satisfy the minimum amount required by applicable law and regulations, or to directly pay benefits where appropriate. As part of the Plan of Reorganization, on December 15, 2017, the Company paid the aggregate unpaid required minimum funding for the APP of $49 million. On March 27, 2020, the Coronavirus Aid, Relief and Economic Security Act ("CARES Act") was signed into law, providing limited relief for pension funding and retirement plan distributions. Under the CARES Act, employers may delay contributions for single employer defined benefit pension plans until January 1, 2021. Contributions to U.S. pension plans were $10 million, $27 million, $43 million and $49 million for fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), respectively. Contributions to the non-U.S. pension plans were $22 million, $23 million, $22 million and $3 million for fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), respectively. In fiscal 2021, the Company estimates that it will make contributions totaling $18 million to satisfy the minimum statutory funding requirements in the U.S. and contributions totaling $24 million for non-U.S. plans. Other changes in plan assets and benefit obligations recognized in other comprehensive (loss) income are provided in the tables below: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 Pension Benefits - U.S. Net loss (gain) $ 31 $ 94 $ (15) $ — Amortization of actuarial loss — — — (20) Reorganization adjustments — — — (1,147) Total recognized in Other comprehensive (loss) income $ 31 $ 94 $ (15) $ (1,167) Total recognized in net periodic benefit cost and Other comprehensive (loss) income (1) $ 9 $ 77 $ (35) $ (722) Pension Benefits - Non-U.S. Net (gain) loss $ (33) $ 76 $ (19) $ 22 Foreign exchange rate loss — (2) — — Amortization of actuarial loss — — — (2) Reorganization adjustments — — — (163) Total recognized in Other comprehensive (loss) income $ (33) $ 74 $ (19) $ (143) Total recognized in net periodic benefit cost and Other comprehensive (loss) income (1) $ (22) $ 89 $ (7) $ (137) Post-retirement Benefits - U.S. Net loss (gain) $ 20 $ 36 $ (34) $ — Prior service credit — (7) — — Amortization of prior service credit 1 — — 3 Amortization of actuarial gain (loss) — 1 — (2) Reorganization adjustments — — — (40) Total recognized in Other comprehensive (loss) income $ 21 $ 30 $ (34) $ (39) Total recognized in net periodic benefit cost and Other comprehensive (loss) income (1) $ 22 $ 35 $ (30) $ 2 (1) For the period from October 1, 2017 through December 15, 2017, the U.S.; non-U.S.; and other Post-retirement benefits include Plan of Reorganization settlements that were recorded in Reorganization items, net in the Consolidated Statements of Operations of $(440) million, $0 million and $(43) million, respectively. The estimated amount to be amortized from Accumulated other comprehensive loss as a net periodic cost during fiscal 2021 is $3 million, consisting of the recognition of net actuarial expense for the Company's U.S. pension plan and post-retirement benefit plan of $2 million and $2 million, respectively, partially offset by the recognition of a prior service credit for the Company's post-retirement benefit plan of $1 million. The discount rate is subject to change each year, consistent with changes in rates of return on high-quality fixed-income investments currently available and expected to be available during the expected benefit payment period. The Company selects the assumed discount rate for its U.S. pension and post-retirement benefit plans by applying the rates from the Aon AA Above Median and Aon AA Only Bond Universe yield curves to the expected benefit payment streams and develops a rate at which it is believed the benefit obligations could be effectively settled. The Company follows a similar process for its non-U.S. pension plans by applying the Aon Euro AA corporate bond yield curve for the plans based in Europe and relevant country-specific bond indices for other locations. Based on the published rates as of September 30, 2020, the Company used a weighted average discount rate of 2.50% for the U.S. pension plans, 0.86% for the non-U.S. pension plans and 2.69% for the post-retirement plans, a decrease of 59 basis points, 1 basis points and 48 basis points from the prior year for the U.S. pension plans, the non-U.S. pension plans and the post-retirement benefit plans, respectively. As of September 30, 2020, this had the effect of increasing the projected U.S. pension, non-U.S. pension and post-retirement benefit obligations by $66 million, $2 million and $25 million, respectively. For fiscal 2021, this will have a minimal effect on the U.S. pension and post-retirement service cost. The expected long-term rate of return on U.S. pension and post-retirement benefit plan assets is selected by applying forward-looking capital market assumptions to the strategic asset allocation approved by the governing body for each plan. The forward-looking capital market assumptions are developed by an investment adviser and reviewed by the Company for reasonableness. The return and risk assumptions consider such factors as anticipated long-term performance of individual asset classes, risk premium for active management based on qualitative and quantitative analysis, and correlations of the asset classes that comprise the asset portfolio. The Company’s cost for post-retirement healthcare claims is capped and the projected post-retirement healthcare claims exceed the cap. Therefore, a one-percentage-point increase or decrease in the Company’s healthcare cost trend rates will not impact the post-retirement benefit obligation and the service and interest cost components of net periodic benefit cost. The weighted average asset allocation of the pension and post-retirement plans by asset category and target allocation is as follows: As of September 30, Asset Category 2020 2019 Long-term Target Pension Benefits - U.S. Debt Securities 52 % 52 % 52 % Equity Securities 29 % 29 % 34 % Hedge Funds 6 % 7 % 6 % Real Estate 5 % 6 % 6 % Commodities 2 % 2 % 2 % Other (1) 6 % 4 % — % Total 100 % 100 % 100 % Pension Benefits - Non-U.S. Debt Securities 22 % 27 % Asset Allocation Fund 11 % 13 % Insurance Contracts 67 % 60 % Total 100 % 100 % Post-retirement Benefits - U.S. Equity Securities 34 % 40 % 35 % Debt Securities 66 % 60 % 65 % Total 100 % 100 % 100 % (1) Other includes cash/cash equivalents, derivative financial instruments and payables/receivables for pending transactions. The Company’s asset management strategy focuses on the dual objectives of improving the funded status of the pension plans and reducing the impact of changes in interest rates on the funded status. To improve the funded status of the pension plans, assets are invested in a diversified mix of asset classes designed to generate higher returns over time, than the pension benefit obligation discount rate assumption. To reduce the impact of interest rate changes on the funded status of the pension plans, assets are invested in a mix of fixed income investments (including long-term debt) that are selected based on the characteristics of the benefit obligation of the pension plans. Strategic asset allocation is the principal method for achieving the Company’s investment objectives, which are determined in the course of periodic asset-liability studies. The most recent asset-liability study was completed in 2019 for the pension plans. As part of the Company’s asset management strategy, investments are professionally managed and diversified across multiple asset classes and investment styles to minimize exposure to any one specific investment. Derivative instruments (such as forwards, futures, swaptions and swaps) may be held as part of the Company’s asset management strategy. However, the use of derivative financial instruments for speculative purposes is prohibited by the Company’s investment policy. Also, as part of the Company’s investment strategy, the U.S. pension plans invest in hedge funds, real estate funds, private equity and commodities to provide additional uncorrelated returns. The fair value of plan assets is determined by the trustee and reviewed by the Company, in accordance with the accounting guidance for fair value measurements and the fair value hierarchy discussed in Note 13, "Fair Value Measurements." Because of the inherent uncertainty of valuation, estimated fair values may differ significantly from the fair values that would have been used had quoted prices in an active market existed. The following table summarizes the fair value measurements of the U.S. pension plan assets by asset class: As of September 30, 2020 As of September 30, 2019 (In millions) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total U.S. Government debt securities (a) $ — $ 132 $ — $ 132 $ — $ 125 $ — $ 125 Derivative instruments (b) — — — — (2) — — (2) Total assets in the fair value hierarchy — 132 — 132 (2) 125 — 123 Investments measured at net asset value: (c) Real estate (d) 50 55 Private equity (e) 2 4 Multi-strategy hedge funds (f) 56 65 Investment funds: (g) Cash equivalents 46 37 Long duration fixed income 327 328 High-yield debt 19 19 U.S. equity 154 144 Non-U.S. equity 83 92 Emerging market equity 33 29 Commodities 20 14 Total investments measured at net asset value 790 787 Other plan assets, net 5 5 Total plan assets at fair value $ — $ 132 $ — $ 927 $ (2) $ 125 $ — $ 915 (a) Includes U.S. Treasury STRIPS, which are generally valued using institutional bid evaluations from various contracted pricing vendors. Institutional bid evaluations are estimated prices that represent the price a dealer would pay for a security. Pricing inputs to the institutional bid evaluation vary by security and include benchmark yields, reported trades, unadjusted broker/dealer quotes, issuer spreads, bids, offers or other observable market data. (b) Includes future contracts that are generally valued using the last trade price at which a specific contract/security was last traded on the primary exchange, which is provided by a contracted vendor. If pricing is not available from the contracted vendor, then pricing is obtained from other sources such as Bloomberg, broker bid, ask/offer quotes or the investment manager. (c) These investments are measured at fair value using the net asset value per share or its equivalent ("NAV") and have therefore not been classified in the fair value hierarchy. (d) Includes open ended real estate commingled funds, close ended real estate limited partnerships, and insurance company separate accounts that invest primarily in U.S. office, lodging, retail and residential real estate. The insurance company separate accounts and the commingled funds account for their portfolio of assets at fair value and calculate the NAV on either a monthly or quarterly basis. Shares can be redeemed at the NAV on a quarterly basis, provided a written redemption request is received in advance (generally 45-91 days) of the redemption date. Therefore, the undiscounted NAV is used as the fair value measurement. For limited partnerships, the fair value of the underlying assets and the capital account for each investor is determined by the General Partner ("GP"). The valuation techniques used by the GP generally consist of unobservable inputs such as discounted cash flow analysis, analysis of recent comparable sales transactions, actual sale negotiations and bona fide purchase offers received from third parties. The partnerships are typically funded over time as capital is needed to fund asset purchases, and distributions from the partnerships are received as the partnerships liquidate their underlying asset holdings. Therefore, the life cycle for a typical investment in a real estate limited partnership is expected to be approximately 10 years from initial funding. (e) Includes limited partner interests in various limited partnerships ("LPs") that invest primarily in U.S. and non-U.S. investments either directly, or through other partnerships or funds with a focus on venture capital, buyouts, expansion capital, or companies undergoing financial distress or significant restructuring. The NAV of the LPs and of the capital account of each investor is determined by the GP of each LP. Marketable securities held by the LPs are valued based on the closing price on the valuation date on the exchange where they are principally traded and may be adjusted for legal restrictions, if any. Investments without a public market are valued based on assumptions made and valuation techniques used by the GP, which consist of unobservable inputs. Such valuation techniques may include discounted cash flow analysis, analysis of recent comparable sales transactions, actual sale negotiations and bona fide purchase offers received from third parties. The LPs are typically funded over time as capital is needed to fund purchases and distributions are received as the partnerships liquidate their underlying asset holdings. (f) Includes hedge funds and funds of funds that pursue multiple strategies to diversify risks and reduce volatility. The funds account for their portfolio of assets at fair value and calculate the NAV of their fund on a monthly basis. The funds limit the frequency of redemptions to manage liquidity and protect the interests of the funds and its shareholders. (g) Includes open-end funds and unit investment trusts that invest in various asset classes including: U.S. and non-U.S. corporate debt, U.S. government debt, municipal bonds, U.S. equity, non-U.S. developed and emerging markets equity, and commodities. The funds account for their portfolio of assets at fair value and calculate the NAV of the funds on a daily basis, and shares can be redeemed at the NAV. Therefore, the undiscounted NAV as reported by the funds is used as the fair value measurement. The following table summarizes the fair value of the non-U.S. pension plan assets by asset class: As of September 30, (In millions) 2020 2019 Investments measured at net asset value: (a) Investment funds: (b) Debt securities $ 4 $ 4 Asset allocation 2 2 Insurance contracts (c) 12 9 Total plan assets at fair value $ 18 $ 15 (a) These investments are measured at fair value using the NAV and have therefore not been classified in the fair value hierarchy. (b) Includes collective investment funds that invest in various asset classes including U.S. and non-U.S. corporate debt and equity, and derivatives. The funds account for their portfolio of assets at fair value and calculate the NAV of the funds on a daily basis, and shares can be redeemed at the NAV. Therefore, the undiscounted NAV as reported by the funds is used as the fair value measurement. (c) Most non-U.S. pension plans are funded through insurance contracts, which provide for a guaranteed interest credit and a profit-sharing adjustment based on the actual performance of the underlying investment assets of the insurer. The fair value of the contract is determined by the insurer based on the premiums paid by the Company plus interest credits plus the profit-sharing adjustment less benefit payments. The underlying assets of the insurer are invested in compliance with local rules or law, which tend to require a high allocation to fixed income securities. The following table summarizes the fair value of the post-retirement plan assets by asset class: As of September 30, (In millions) 2020 2019 Investments measured at net asset value: (a) Group life insurance contract measured at net asset value (b) $ 206 $ 191 Total plan assets at fair value $ 206 $ 191 (a) These investments are measured at fair value using the NAV and have therefore not been classified in the fair value hierarchy. (b) The group life insurance contracts are held in a reserve of an insurance company that provides for investment of pre-funding amounts in a family of pooled separate accounts. The fair value of each group life insurance contract is primarily determined by the value of the units it owns in the pooled separate accounts that back the policy. Each of the pooled separate accounts provides a unit NAV on a daily basis, which is based on the fair value of the underlying assets owned by the account. The post-retirement benefit plans can transact daily at the unit NAV without restriction. As of September 30, 2020, the asset allocation of the pooled separate accounts in which the contracts invest was approximately 66% fixed income securities, 24% U.S. equity securities and 10% non-U.S. equity securities. Savings Plans Substantially all of the Company’s U.S. employees are eligible to participate in savings plans sponsored by the Company. The plans allow employees to contribute a portion of their compensation on a pre-tax and after-tax basis in accordance with specified guidelines. The Company matches a percentage of employee contributions up to certain limits. The Company's expense related to these savings plans was $8 million, $8 million, $7 million and $0 million for fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor).

Share-based Compensation

Share-based Compensation	12 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Share-based Compensation	Share-based Compensation The Predecessor Company's common and preferred stock were canceled and new common stock was issued on the Emergence Date. Accordingly, the Predecessor Company’s then existing share-based compensation awards were also canceled, which resulted in the recognition of any previously unamortized expense on the date of cancellation. As a result, share-based compensation for the Successor and Predecessor periods are not comparable. Successor 2017 Equity Incentive Plan On the Emergence Date, the Company adopted the Avaya Holdings Corp. 2017 Equity Incentive Plan (the "2017 Plan"), under which non-employee directors, employees of the Company or any of its affiliates, and certain consultants and advisors may be granted stock options, restricted stock, restricted stock units ("RSUs"), performance awards ("PRSUs") and other forms of awards granted or denominated in shares of the Company's common stock, as well as certain cash-based awards. 2019 Equity Incentive Plan On November 13, 2019, the Board of Directors of the Company (the "Board") approved the Avaya Holdings Corp. 2019 Equity Incentive Plan and on January 8, 2020 approved an amendment to such plan (as so amended, the "2019 Plan"). On November 13, 2019, the Board also adopted the 2019 Omnibus Inducement Equity Plan (the "Inducement Plan"), which reserved up to 1,700,000 shares of the Company's common stock for awards to be made to certain prospective employees pursuant to the "inducement grant" exemption under the NYSE Listing Rules. On March 4, 2020, the stockholders of the Company approved the 2019 Plan and, as of such date, no additional awards may be granted under the 2017 Plan or the Inducement Plan (together, the "Prior Plans"). The Board or any committee duly authorized thereby administers the 2019 Plan. The administrator has broad authority to, among other things: (i) select participants; (ii) determine the types of awards that participants are to receive and the number of shares that are to be granted under such awards; and (iii) establish the terms and conditions of awards, including the price to be paid for the shares or the awards. The 2019 Plan provides an initial pool of 18,800,000 shares of common stock (the "Initial Pool") that may be issued or granted, which can be adjusted for shares that become available from existing awards issued under the Prior Plans in accordance with the terms of the 2019 Plan. The Initial Pool will be reduced by one share of common stock for every option granted and 1.7 shares for any awards granted other than options . As of September 30, 2020, there were 14,407,473 shares available to be granted under the 2019 Plan. If any awards granted under the 2019 Plan expire, terminate or are canceled or forfeited for any reason without having been exercised in full, the number of shares of common stock underlying any unexercised award will again be available for issuance under the 2019 Plan. Any award under the 2019 Plan settled in cash will not be counted against the foregoing maximum share limitations. Shares withheld by the Company in satisfaction of the applicable exercise price or withholding taxes upon the issuance, vesting or settlement of awards, shares reacquired by the Company on the open market or otherwise using cash proceeds from the exercise of options, in each case, shall not be available for future issuance under the 2019 Plan or the Prior Plans. Stock options and RSUs granted to employees generally vest ratably over a period of three years. PRSUs granted to certain senior executive employees vest at the end of a three year service period. Awards granted to non-employee directors during fiscal 2020 and 2019 vest immediately, while those granted during the period from December 16, 2017 through September 30, 2018 vested ratably over one year. The aggregate grant date fair value of all awards granted to any non-employee director during any fiscal year (excluding awards made pursuant to deferred compensation arrangements made in lieu of all or a portion of cash retainers and any dividends payable in respect of outstanding awards) may not exceed $750,000. As of the Emergence Date, forfeitures are accounted for as incurred. Pre-tax share-based compensation expense for fiscal 2020, fiscal 2019 and the period from December 16, 2017 through September 30, 2018 was $30 million, $25 million and $19 million and the income tax benefit recognized in the Consolidated Statements of Operations for share-based compensation arrangements was $2 million, $2 million and $1 million, respectively. Restricted Stock Units Compensation cost for RSUs granted to employees and non-employee directors is generally measured by using the closing market price of the Company's common stock at the date of grant. A summary of RSU activity for fiscal 2020 is presented below: Restricted Stock Units Weighted Average Grant-Date Fair Value Non-vested at September 30, 2019 2,797 $ 15.60 Granted 2,128 12.42 Vested (1,533) 15.31 Forfeited (698) 15.30 Non-vested at September 30, 2020 2,694 $ 13.32 As of September 30, 2020, there was $31 million of unrecognized share-based compensation expense related to RSUs, which is expected to be recognized over a period up to 2.9 years, or 2.0 years on a weighted average basis. The weighted average grant date fair value for RSUs granted during fiscal 2020, fiscal 2019 and the period from the Emergence Date through September 30, 2018 was $12.42, $15.29 and $16.11, respectively. The total grant date fair value of RSUs vested during fiscal 2020, fiscal 2019 and the period from the Emergence Date through September 30, 2018 was $23 million, $27 million and $6 million, respectively. Performance Restricted Stock Units The Company grants PRSUs which vest based on the attainment of specified performance metrics for each of the next three separate fiscal years (collectively the "Performance Period"), and the Company's total shareholder return over the Performance Period as compared to the total shareholder return for a specified index of companies over the same period (the “Performance PRSUs”). During the Performance Period, the Company adjusts compensation expense for the Performance PRSUs based on its best estimate of attainment of the specified annual performance metrics. The cumulative effect on current and prior periods of a change in the estimated number of Performance PRSUs that are expected to be earned during the Performance Period is recognized as an adjustment to earnings in the period of the revision. The weighted average grant date fair value for Performance PRSUs granted during fiscal 2020 and 2019 was $13.69 and $17.39, respectively. There were no Performance PRSUs granted during the period from December 16, 2017 through September 30, 2018. The grant date fair value of the Performance PRSUs was determined using a Monte Carlo simulation model that incorporated multiple valuation assumptions, including the probability of achieving the total shareholder return market condition and the following assumptions presented on a weighted-average basis: Fiscal years ended September 30, 2020 2019 Expected volatility (1) 55.75 % 53.00 % Risk-free interest rate (2) 1.61 % 2.46 % Dividend yield (3) — % — % (1) Expected volatility based on a blend of Company and peer group company historical data adjusted for the Company's leverage. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the remaining Performance Period as of the grant date. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends. The Company has also granted PRSUs which become eligible to vest if prior to the vesting date the average closing price of one share of the Company’s Common Stock for sixty consecutive days equals or exceeds a specified price (the “Market PRSUs”). The grant date fair value of the Market PRSUs is recognized as expense ratably over the vesting period and is not adjusted in future periods for the success or failure to achieve the specified market condition. The grant date fair value of Market PRSUs granted during fiscal 2019 was $11.18. There were no Market PRSUs granted during fiscal 2020 or the period from December 16, 2017 through September 30, 2018. The grant date fair value of Market PRSUs was determined using a Monte Carlo simulation model that incorporated multiple valuation assumptions, including the probability of achieving the specified market condition and the following assumptions: Fiscal year ended Expected volatility (1) 53.76 % Risk-free interest rate (2) 2.45 % Dividend yield (3) — % (1) Expected volatility based on a blend of Company and peer group company historical data adjusted for the Company's leverage. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the remaining Performance Period as of the grant date. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends. A summary of total PRSU activity for fiscal 2020 is presented below: Performance Restricted Stock Units Weighted Average Grant-Date Fair Value Non-vested at September 30, 2019 274 $ 11.18 Granted 662 13.69 Change in shares due to performance (314) 13.71 Forfeited (34) 13.29 Non-vested at September 30, 2020 588 $ 12.53 As of September 30, 2020, there was $5 million of unrecognized share-based compensation expense related to PRSUs, which is expected to be recognized over a period of 2.4 years or 2.1 years on a weighted average basis. Stock Options A lattice option pricing model was used to determine the fair value of options granted on the Emergence Date as they were premium priced options. The Black-Scholes option pricing model is used to value all options granted after the Emergence Date. The weighted average grant date fair value of options granted in fiscal 2020 and the period from the Emergence Date through September 30, 2018 was $6.11 and $8.18, respectively. There were no options granted during fiscal 2019. The weighted average grant date assumptions used in calculating the fair value of options granted on the Emergence Date and thereafter were as follows: Fiscal year ended Period from December 16, 2017 Emergence Date Exercise price $ 11.38 $ 21.66 $ 19.46 Expected volatility (1) 56.76 % 49.67 % 56.59 % Expected life (in years) (2) 5.97 5.86 6.65 Risk-free interest rate (3) 1.71 % 2.72 % 2.35 % Dividend yield (4) — % — % — % (1) Expected volatility based on peer group companies adjusted for the Company's leverage. (2) Expected life based on the vesting terms of the option and a contractual life of ten years. (3) Risk-free interest rate based on U.S. Treasury yields with a term equal to the expected option term. (4) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends. A summary of option activity for fiscal 2020 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at September 30, 2019 925 $ 19.59 Granted 164 11.38 Forfeited or expired (147) 19.84 Outstanding at September 30, 2020 942 $ 18.13 7.3 $ 625 Exercisable at September 30, 2020 715 $ 19.54 6.9 $ — The intrinsic value is the difference between the Company's common stock price and the option exercise price. There were no stock options exercised during fiscal 2020 and 2019. The total pretax intrinsic value of stock options exercised for the period from December 16, 2017 through September 30, 2018 was not material. As of September 30, 2020, there was $1 million of unrecognized share-based compensation expense related to stock options, which is expected to be recognized over a period up to 2.4 years, or 1.5 years on a weighted average basis. The total grant date fair value of stock options vested during fiscal 2020, fiscal 2019 and the period from December 16, 2017 through September 30, 2018 was $2 million, $4 million and $1 million respectively. Employee Stock Purchase Plan On January 8, 2020, the Board approved the Avaya Holdings Corp. 2020 Employee Stock Purchase Plan ("ESPP"). A maximum of 5,500,000 shares of the Company's common stock has been reserved for issuance under the ESPP. Under the ESPP, eligible employees may purchase the Company's common stock through payroll deductions at a discount not to exceed 15% of the lower of the fair market values of the Company's common stock as of the beginning or end of each 3-month offering period. Payroll deductions are limited to 10% of the employee's eligible compensation and a maximum of 6,250 shares of the Company's common stock may be purchased by an employee each offering period. The first offering period began on June 1, 2020. During fiscal 2020, the Company withheld $3 million of eligible employee compensation for purchases of common stock and issued 204,445 shares under the ESPP. As of September 30, 2020, 5,295,555 shares of common stock were available for future issuance under the ESPP. The grant date fair value for shares issued under the ESPP is measured on the date that each offering period commences. The average grant date fair value for the offering periods that commenced during fiscal 2020 was $4.99 per share. The grant date fair value was determined using a Black-Scholes option pricing model with the following average grant date assumptions: Fiscal year ended Expected volatility (1) 93.51 % Risk-free interest rate (2) 0.13 % Dividend yield (3) — % (1) Expected volatility based on the Company's historical data. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the length of the offering period. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends. As of September 30, 2020, there was $0.4 million of unrecognized share-based compensation expense related to the ESPP, which is expected to be recognized over a period of 0.2 years. Predecessor Prior to the Emergence Date, the Predecessor Company had granted share-based awards that were canceled upon emergence from bankruptcy. In conjunction with the cancellation, the Predecessor Company accelerated the unrecognized share-based compensation expense and recorded $3 million of compensation expense in the period from October 1, 2017 through December 15, 2017, principally reflected in Reorganization costs, net. No income tax benefit was recognized in the income statement for share-based compensation arrangements for the period from October 1, 2017 through December 15, 2017. Option Awards Under the terms of the Predecessor Company's equity incentive plan, stock options could not be granted with an exercise price of less than the fair market value of the underlying stock on the date of grant. Share-based compensation expense recognized in the Consolidated Statements of Operations was based on awards ultimately expected to vest. Forfeitures were estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differed from those estimates in accordance with the authoritative guidance. All options awarded under the Predecessor Company's equity incentive plan expired the earlier of ten years from the date of grant or upon cessation of employment, in which event there were limited exercise provisions allowed for vested options. Subsequent to October 1, 2012, the Company granted time-based options to purchase Predecessor common stock. Time-based options vested over their performance periods and were payable in shares of common stock upon vesting and exercise. The performance period for time-based options was generally three During the period from October 1, 2017 through December 15, 2017, there were no options granted or exercised and 19,842,268 options were canceled upon the Company’s emergence from bankruptcy. Restricted Stock Units Avaya Holdings had issued RSUs, each of which represented the right to receive one share of its Predecessor common stock when fully vested. The fair value of the common stock underlying the RSUs was estimated by the Compensation Committee of Avaya Holdings’ Board of Directors at the date of grant.

Capital Stock

Capital Stock	12 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Capital Stock	Capital Stock Successor Preferred Stock The Successor Company's certificate of incorporation authorizes it to issue up to 55,000,000 shares of preferred stock with a par value of $0.01 per share. On October 31, 2019, the Company issued 125,000 shares of its 3% Series A Convertible Preferred Stock, par value $0.01 per share ("Series A Preferred Stock"), to RingCentral for an aggregate purchase price of $125 million. The Series A Preferred Stock is convertible into shares of the Company's common stock at an initial conversion price of $16.00 per share, which represents an approximately 9% interest in the Company's common stock on an as-converted basis as of September 30, 2020, assuming no holders of options, warrants, convertible notes or similar instruments exercise their exercise or conversion rights. The holders of the Series A Preferred Stock are entitled to vote, on an as-converted basis, together with holders of the Company's common stock on all matters submitted to a vote of the holders of the common stock. Holders of the Series A Preferred Stock are entitled to receive dividends, in preference and priority to holders of the Company's common stock, which accrue on a daily basis at the rate of 3% per annum of the stated value of the Series A Preferred Stock. The stated value of the Series A Preferred Stock was initially $1,000 per share and will be increased by the sum of any dividends on such shares not paid in cash. These dividends are cumulative and compound quarterly. The holders of the Series A Preferred Stock participate in any dividends the Company pays on its common stock, equal to the dividend which holders would have received if their Series A Preferred Stock had been converted into common stock on the date such common stock dividend was determined. In the event the Company is liquidated or dissolved, the holders of the Series A Preferred Stock are entitled to receive an amount equal to the liquidation preference (which equals the then stated value plus any accrued and unpaid dividends) for each share of Series A Preferred Stock before any distribution is made to holders of the Company's common stock. The Series A Preferred Stock are redeemable at the Company's election upon the termination of the Framework Agreement. In addition, the holders of the Series A Preferred Stock have certain rights to require the Company to redeem or put rights to require the Company to repurchase all or any portion of the Series A Preferred Stock. The holders can exercise such redemption rights, upon at least 21 days' notice, after the termination of the Framework Agreement or upon the occurrence of certain events. If and to the extent the redemption right is exercised, the Company would be required to purchase each share of Series A Preferred Stock at the per share price equal to the stated value of the Series A Preferred Stock which will be increased by the sum of any dividends on such shares that have accrued and have been paid in kind, plus all accrued but unpaid dividends. Given that the holders of the Series A Preferred Stock may require the Company to redeem all or a portion of its shares, the Series A Preferred Stock is classified in the mezzanine section of the Consolidated Balance Sheets between Total liabilities and Stockholders' equity. As of September 30, 2020, the carrying value of the Series A Preferred Stock was $128 million, which includes $3 million of accreted dividends paid in kind. In connection with the issuance of the Series A Preferred Stock, the Company granted RingCentral certain customary consent rights with respect to certain actions by the Company, including amending the Company's organizational documents in a manner that would have an adverse effect on the Series A Preferred Stock and issuing securities that are senior to, or equal in priority with, the Series A Preferred Stock. In addition, pursuant to an Investor Rights Agreement, until such time when RingCentral and its affiliates hold or beneficially own less than 4,759,339 shares of the Company's common stock (on an as-converted basis), RingCentral has the right to nominate one person for election to the Company's Board of Directors. The director designated by RingCentral has the option (i) to serve on the Company's Audit and Nominating and Corporate Governance Committees or (ii) to attend (but not vote at) all of the Company's Board of Directors' committee meetings. During the fourth quarter of fiscal 2020, RingCentral nominated Robert Theis for election to the Company's Board of Directors. On November 6, 2020, Robert Theis was elected to join the Board. As of September 30, 2020, there were 125,000 shares of preferred stock outstanding. There were no preferred shares outstanding as of September 30, 2019. Common Stock The Successor Company's certificate of incorporation authorizes it to issue up to 550,000,000 shares of common stock with a par value of $0.01 per share. As of September 30, 2020, there were 83,278,383 shares issued and outstanding. As of September 30, 2019, there were 111,046,085 shares issued and 111,033,405 shares outstanding with the remaining 12,680 shares distributable in accordance with the Plan of Reorganization. On November 14, 2018, the Company's Board of Directors approved a warrant repurchase program, authorizing the Company to repurchase Emergence Date Warrants for an aggregate expenditure of up to $15 million. The repurchases may be made from time to time in the open market, through block trades or in privately negotiated transactions. The Company may adopt one or more purchase plans pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended, in order to implement the warrant repurchase program. The warrant repurchase program does not obligate the Company to purchase any warrants and may be terminated, increased or decreased by the Board of Directors in its discretion at any time. As of September 30, 2020, there were no warrant repurchases under the program. On October 1, 2019, the Board of Directors of the Company approved a share repurchase program authorizing the Company to repurchase the Company's common stock for an aggregate expenditure of up to $500 million. The repurchases may be made from time to time in the open market, through block trades or in privately negotiated transactions. The Company adopted a purchase plan pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended, to implement the share repurchase program. The share repurchase program does not obligate the Company to purchase any common stock and may be terminated, increased or decreased by the Board in its discretion at any time. All shares that are repurchased under the program are retired by the Company. During fiscal 2020, the Company repurchased 28,923,664 shares of its common stock at a weighted average price per share of $11.41, including transaction costs. As of September 30, 2020, the remaining authorized amount for share repurchases under this program was $170 million. Predecessor In connection with the Successor Company’s Plan of Reorganization and emergence from bankruptcy, all equity interests in the Predecessor Company were canceled, including preferred and common stock, warrants and equity-based awards. As a result, the carrying value of the Predecessor Company’s equity interests were adjusted to $0 during the period from October 1, 2017 through December 15, 2017. See Note 24, “Fresh Start Accounting,” for additional information.

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share	12 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Income (Loss) Per Common Share	(Loss) Earnings Per Common Share Basic (loss) earnings per share is calculated by dividing net (loss) income attributable to common stockholders by the weighted average number of common shares outstanding. Diluted (loss) earnings per share reflects the potential dilution that would occur if equity awards granted under the Company's various share-based compensation plans were vested or exercised; if the Company’s Series A Preferred Stock were converted into shares of the Company’s common stock; if the Company's Convertible Notes or the warrants the Company sold to purchase up to 12.6 million shares of its common stock in connection with the issuance of Convertible Notes ("Call Spread Warrants") were exercised; and/or if the Emergence Date Warrants were exercised, resulting in the issuance of common shares that would participate in the earnings of the Company. The following table sets forth the calculation of net (loss) income attributable to common shareholders and the computation of basic and diluted (loss) earnings per share for the periods indicated: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions, except per share amounts) 2020 2019 (Loss) Earnings per share: Numerator Net (loss) income $ (680) $ (671) $ 287 $ 2,977 Dividends and accretion to preferred stockholders (7) — — (6) Undistributed (loss) income (687) (671) 287 2,971 Percentage allocated to common stockholders (1) 100.0 % 100.0 % 100.0 % 86.9 % Numerator for basic and diluted (loss) earnings per common share $ (687) $ (671) $ 287 $ 2,582 Denominator Denominator for basic (loss) earnings per weighted average common shares 92.2 110.8 109.9 497.3 Effect of dilutive securities Restricted stock units — — 1.2 — Denominator for diluted (loss) earnings per weighted average common shares 92.2 110.8 111.1 497.3 (Loss) earnings per common share Basic $ (7.45) $ (6.06) $ 2.61 $ 5.19 Diluted $ (7.45) $ (6.06) $ 2.58 $ 5.19 (1) Basic weighted average common stock outstanding 92.2 110.8 109.9 497.3 Basic weighted average common stock and common stock equivalents (preferred shares) 92.2 110.8 109.9 572.4 Percentage allocated to common stockholders 100.0 % 100.0 % 100.0 % 86.9 % The Company's preferred stock are participating securities, which requires the application of the two-class method to calculate basic and diluted earnings per share. Under the two-class method, undistributed earnings are allocated to common stock and participating securities according to their respective participating rights in undistributed earnings, as if all the earnings for the period had been distributed. Basic (loss) earnings per common share is computed by dividing the net (loss) income attributable to common stockholders by the weighted average number of common shares outstanding during the period. Net (loss) income attributable to common stockholders is reduced for preferred stock dividends earned and accretion recognized during the period. No allocation of undistributed earnings to participating securities was performed for periods with net losses as such securities do not have a contractual obligation to share in the losses of the Company. For fiscal 2020, the Company excluded 0.9 million stock options, 2.7 million RSUs, 0.2 million shares issuable under the ESPP, 0.1 million shares of Series A Preferred Stock and 5.6 million Emergence Date Warrants from the diluted loss per share calculation as their effect would have been anti-dilutive. The Company also excluded 1.0 million PRSUs from the diluted loss per share calculation as either their performance metrics have not been attained or their effect would have been anti-dilutive. For fiscal 2019, the Company excluded 0.9 million stock options, 2.8 million RSUs and 5.6 million Emergence Date Warrants from the diluted loss per share calculation as their effect would have been anti-dilutive. The Company also excluded 0.5 million PRSUs from the diluted loss per share calculation as their performance metrics have not been attained. During the period from December 16, 2017 through September 30, 2018, the Company excluded 1.1 million stock options, 0.2 million restricted stock units and 5.6 million Emergence Date Warrants to purchase common shares from the diluted earnings per share calculation as their effect would have been anti-dilutive. The Company’s Convertible Notes and Call Spread Warrants were also excluded from the diluted (loss) earnings per share calculation for fiscal 2020 and 2019 and the period from December 16, 2017 through September 30, 2018 as their effect would have been anti-dilutive. For purposes of considering the Convertible Notes in determining diluted (loss) earnings per share, the Company has the ability and current intent to settle conversions of the Convertible Notes through combination settlement by repaying the principal portion in cash and any excess of the conversion value over the principal amount (the "Conversion Premium") in shares of the Company's common stock. Therefore, if it would have a dilutive impact, only the impact of the Conversion Premium will be included in diluted weighted average shares outstanding using the treasury stock method. Since the Convertible Notes were out of the money and anti-dilutive as of September 30, 2020, 2019 and 2018, they were excluded from the diluted (loss) earnings per share calculation for fiscal 2020, fiscal 2019 and the period from December 16, 2017 through September 30, 2018. The Call Spread Warrants will not be considered in calculating diluted weighted average shares outstanding until the price per share of the Company’s common stock exceeds the strike price of $37.3625 per share. When the price per share of the Company’s common stock exceeds the strike price per share of the Call Spread Warrants, the effect of the additional shares that may be issued upon exercise of the Call Spread Warrants will be included in diluted weighted average shares outstanding using the treasury stock method.

Operating Segments

Operating Segments	12 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Operating Segments	Operating Segments The Products & Solutions segment primarily develops, markets, and sells unified communications and contact center solutions, offered on premises, in the cloud, or as a hybrid solution. These integrate multiple forms of communications, including telephony, email, instant messaging and video. The Services segment develops, markets and sells comprehensive end-to-end global service offerings that enable customers to evaluate, plan, design, implement, monitor, manage and optimize complex enterprise communications networks. Revenue from customers who upgrade and acquire new technology through the Company's subscription offerings is reported within the Services segment. The Company’s chief operating decision maker makes financial decisions and allocates resources based on segment profit information obtained from the Company’s internal management systems. Management does not include in its segment measures of profitability selling, general and administrative expenses, research and development expenses, amortization of intangible assets, and certain discrete items, such as fair value adjustments recognized upon emergence from bankruptcy, charges relating to restructuring actions, impairment charges, and merger-related costs as these costs are not core to the measurement of segment performance, but rather are controlled at the corporate level. Summarized financial information relating to the Company's operating segments is shown in the following table for the periods indicated: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 REVENUE Products & Solutions $ 1,074 $ 1,228 $ 1,052 $ 253 Services 1,805 1,680 1,401 351 Unallocated Amounts (1) (6) (21) (206) — $ 2,873 $ 2,887 $ 2,247 $ 604 GROSS PROFIT Products & Solutions $ 669 $ 791 $ 696 $ 169 Services 1,092 996 843 196 Unallocated Amounts (2) (181) (212) (396) (3) 1,580 1,575 1,143 362 OPERATING EXPENSES Selling, general and administrative 1,013 1,001 888 264 Research and development 207 204 172 38 Amortization of intangible assets 161 162 127 10 Impairment charges 624 659 — — Restructuring charges, net 30 22 81 14 2,035 2,048 1,268 326 OPERATING (LOSS) INCOME (455) (473) (125) 36 INTEREST EXPENSE, OTHER INCOME (EXPENSE), NET AND REORGANIZATION ITEMS, NET (163) (196) (134) 3,400 (LOSS) INCOME BEFORE INCOME TAXES $ (618) $ (669) $ (259) $ 3,436 (1) Unallocated amounts in Revenue represent the fair value adjustment to deferred revenue recognized upon emergence from bankruptcy and excluded from segment revenue. (2) Unallocated amounts in Gross Profit include the fair value adjustments recognized upon emergence from bankruptcy and excluded from segment gross profit; the effect of the amortization of technology intangibles; and costs that are not core to the measurement of segment management’s performance, but rather are controlled at the corporate level. As of September 30, (In millions) 2020 2019 ASSETS: Products & Solutions $ 31 $ 662 Services 1,501 1,504 Unallocated Assets (1) 4,699 4,784 Total $ 6,231 $ 6,950 (1) Unallocated Assets consist of cash and cash equivalents, accounts receivable, contract assets, contract costs, deferred income tax assets, property, plant and equipment, operating lease right-of-use assets, acquired intangible assets and other assets. Unallocated Assets are managed at the corporate level and are not identified with a specific segment. The decrease in Products & Solutions total assets was mainly driven by the $624 million impairment of goodwill recorded during fiscal 2020 as described in Note 7, "Goodwill, net." Geographic Information Financial information relating to the Company’s revenue and long-lived assets by geographic area is as follows: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 REVENUE (1) : U.S. $ 1,640 $ 1,553 $ 1,184 $ 331 International: EMEA 714 753 603 166 APAC—Asia Pacific 296 327 256 57 Americas International—Canada and Latin America 223 254 204 50 Total International 1,233 1,334 1,063 273 Total $ 2,873 $ 2,887 $ 2,247 $ 604 As of September 30, (In millions) 2020 2019 LONG-LIVED ASSETS (2) U.S. $ 191 $ 184 International: EMEA 57 54 APAC—Asia Pacific 13 10 Americas International—Canada and Latin America 7 7 Total International 77 71 Total $ 268 $ 255 (1) Revenue is attributed to geographic areas based on the location of customers. (2) Represents property, plant and equipment, net.

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income	12 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Accumulated Other Comprehensive (Loss) Income	Accumulated Other Comprehensive (Loss) Income The components of Accumulated other comprehensive (loss) income for the periods indicated were as follows: (In millions) Change in Unamortized Pension, Post-retirement and Postemployment Benefit-related Items Foreign Currency Translation Unrealized Loss on Interest Rate Swaps Other Accumulated Other Comprehensive (Loss) Income Balance as of September 30, 2017 (Predecessor) (1,375) (72) — (1) (1,448) Other comprehensive (loss) income before reclassifications (24) 3 — — (21) Amounts reclassified to earnings 16 — — — 16 Pension settlement 721 — — — 721 Provision for income taxes (58) — — — (58) Balance as of December 15, 2017 (Predecessor) (720) (69) — (1) (790) Elimination of Predecessor Company Accumulated other comprehensive loss 720 69 — 1 790 Balance as of December 15, 2017 (Predecessor) $ — $ — $ — $ — $ — Balance as of December 16, 2017 (Successor) $ — $ — $ — $ — $ — Other comprehensive income (loss) before reclassifications 70 (31) (3) — 36 (Provision for) benefit from income taxes (19) — 1 — (18) Balance as of September 30, 2018 (Successor) 51 (31) (2) — 18 Other comprehensive (loss) income before reclassifications (186) 24 (87) — (249) Amounts reclassified to earnings — — 10 — 10 Benefit from income taxes 29 — 19 48 Balance as of September 30, 2019 (Successor) $ (106) $ (7) $ (60) $ — $ (173) Other comprehensive loss before reclassifications (2) (66) (69) — (137) Amounts reclassified to earnings — 27 35 — 62 Benefit from income taxes — — 3 — 3 Balance as of September 30, 2020 (Successor) $ (108) $ (46) $ (91) $ — $ (245) Reclassifications from Accumulated other comprehensive (loss) income related to changes in unamortized pension, post-retirement and postemployment benefit-related items are recorded in Other income (expense), net. Reclassifications from Accumulated other comprehensive (loss) income related to the unrealized loss on interest rate swap agreements are recorded in Interest expense. Reclassifications from Accumulated other comprehensive (loss) income related to foreign currency translation reflect the impact of certain liquidated entities and are recorded in Other income (expense), net.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Successor As of September 30, 2020, the Company's Board of Directors was comprised of seven directors, including the Company's Chief Executive Officer, James M. Chirico, Jr., and six non-employee directors, William D. Watkins, Stephan Scholl, Susan L. Spradley, Stanley J. Sutula, III, Scott D. Vogel and Jacqueline E. Yeaney. On November 6, 2020, Robert Theis was elected to join the Company's Board of Directors as a result of his nomination by RingCentral pursuant to an Investor Rights Agreement entered into in conjunction with the issuance of the Company's Series A Preferred Stock. Specific Arrangements Involving the Successor Company’s Current Directors and Executive Officers William D. Watkins is a Director and Chair of the Board of Directors of the Company and serves on the board of directors of Flex Ltd. ("Flex"), an electronics design manufacturer. During fiscal 2020, the Company sold goods and services to subsidiaries of Flex of $1 million. Sales to Flex during fiscal 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor) were not material. As of September 30, 2020, the Company had outstanding accounts receivable due from Flex of $1 million. Outstanding accounts receivable due from Flex as of September 30, 2019 was not material. During fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), the Company purchased goods and services from subsidiaries of Flex of $23 million, $29 million, $19 million and $6 million, respectively. As of September 30, 2020 and 2019, the Company had outstanding accounts payable due to Flex of $3 million and $6 million, respectively. Effective April 13, 2020, Stephan Scholl, a Director of the Company, assumed the role of Chief Executive Officer of Alight Solutions LLC ("Alight"), a provider of integrated benefits, payroll and cloud solutions. During fiscal 2020, the Company purchased goods and services from subsidiaries of Alight of $5 million. As of September 30, 2020, the Company had outstanding accounts payable due to Alight of $1 million. Specific Arrangements Involving the Successor Company’s Former Directors and Executive Officers Laurent Philonenko was a Senior Vice President of Avaya Holdings through February 15, 2019. While he was a Senior Vice President of Avaya Holdings, Mr. Philonenko served as an Advisor to Koopid, Inc. ("Koopid"), a software development company specializing in mobile communications, a position he had held until January 2018. For the period from December 16, 2017 through September 30, 2018, the Company purchased goods and services from Koopid of $1 million. For the period from October 1, 2017 through December 15, 2017 (Predecessor), purchased goods and services from Koopid were not material. Ronald A. Rittenmeyer was a Director of Avaya Holdings through April 29, 2018. While he was a Director of Avaya Holdings, Mr. Rittenmeyer served on the board of directors of Tenet Healthcare Corporation ("Tenet Healthcare"), a healthcare services company, and also served on the board of directors of American International Group, Inc. ("AIG"), a global insurance organization. For the period from December 16, 2017 through September 30, 2018, sales of the Company’s products and services to Tenet Healthcare were $1 million. For the period from October 1, 2017 through December 15, 2017 (Predecessor), sales of the Company's products and services to Tenet Healthcare were not material. For the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), sales of the Company’s products and services to AIG were $5 million and $2 million, respectively. Predecessor In connection with the acquisition of Avaya Inc., through Avaya Holdings by Silver Lake Partners ("Silver Lake"), TPG Capital ("TPG") and their respective affiliates (collectively, the "Predecessor Sponsors"), in a transaction that was completed on October 26, 2007 (the "Merger"), Avaya Holdings entered into certain stockholder agreements and registration rights agreements with the Predecessor Sponsors and various co-investors. In addition, Avaya Holdings entered into a management services agreement with affiliates of the Predecessor Sponsors and, from time to time, Avaya Holdings entered into various other contracts with companies affiliated with the Predecessor Sponsors. These arrangements terminated upon emergence from bankruptcy. In addition, all Predecessor Company equity held by the Predecessor Sponsors was canceled. No fees were paid to the Predecessor Sponsors in the period from October 1, 2017 through December 15, 2017 (Predecessor). Stockholders’ Agreement In connection with the Merger, Avaya Holdings entered into a stockholders’ agreement with the Predecessor Sponsors and certain of their affiliates. The stockholders’ agreement was amended and restated in connection with the financing of certain acquisitions. The stockholders’ agreement contained certain restrictions on the Predecessor Sponsors’ and their affiliates’ transfer of Avaya Holdings’ equity securities, contained provisions regarding participation rights, contained standard tag-along and drag-along provisions, provided for the election of Avaya Holdings’ directors, mandated board of directors approval of certain matters to include the consent of each Predecessor Sponsor and generally set forth the respective rights and obligations of the stockholders who were parties to that agreement. None of Avaya Holdings’ officers or directors were parties to the agreement, although certain of Avaya Holdings' non-employee directors may have had an indirect interest in the agreement to the extent of their affiliations with the Predecessor Sponsors. This agreement was terminated upon emergence from bankruptcy. Registration Rights Agreement In addition, in connection with the Merger, Avaya Holdings entered into a registration rights agreement with the Predecessor Sponsors and certain of their affiliates, which was amended and restated in connection with the financing of certain acquisitions. Pursuant to the registration rights agreement, as amended, Avaya Holdings would provide the Predecessor Sponsors and certain of their affiliates party thereto with certain demand registration rights. In addition, in the event that Avaya Holdings registered shares of common stock for sale to the public, Avaya Holdings would be required to give notice of such registration to the Predecessor Sponsors and their affiliates party to the agreement of its intention to effect such a registration, and, subject to certain limitations, the Predecessor Sponsors and such holders would have piggyback registration rights providing them with the right to require Avaya Holdings to include shares of common stock held by them in such registration. Avaya Holdings would have been required to bear the registration expenses, other than underwriting discounts and commissions and transfer taxes, if any, associated with any registration of shares by the Predecessor Sponsors or other holders described above. Avaya Holdings had agreed to indemnify each holder of its common stock covered by the registration rights agreement for violations of federal or state securities laws by it in connection with any registration statement, prospectus or any preliminary prospectus. Each holder of such securities had in turn agreed to indemnify Avaya Holdings for federal or state securities law violations that occur in reliance upon written information the holder provided to Avaya Holdings in connection with any registration statement in which a holder of such securities was participating. None of Avaya Holdings’ officers or directors were a party to this agreement, although certain of Avaya Holdings’ non-employee directors may have had an indirect interest in the agreement to the extent of their affiliations with the Predecessor Sponsors. This agreement was terminated upon emergence from bankruptcy. Management Services Agreement and Consulting Services Both Avaya Holdings and Avaya Inc. were party to a Management Services Agreement with Silver Lake Management Company, L.L.C., an affiliate of Silver Lake, and TPG Capital Management, L.P., an affiliate of TPG, collectively "the Managers," pursuant to which the Managers provided management and financial advisory services to the Company. Pursuant to the Management Services Agreement, the Managers received a monitoring fee of $7 million per annum and reimbursement on demand for out-of-pocket expenses incurred in connection with the provision of such services. In the event of a financing, acquisition, disposition or change of control transaction involving the Company during the term of the Management Services Agreement, the Managers had the right to require the Company to pay a fee equal to customary fees charged by internationally-recognized investment banks for serving as a financial advisor in similar transactions. The Management Services Agreement could have been terminated at any time by the Managers, but otherwise had an initial term ending on December 31, 2017 that automatically extended each December 31st for an additional year unless terminated earlier by the Company or the Managers. The term had been automatically extended nine times since the execution of the agreement such that the term was through December 31, 2026. In the event that the Management Services Agreement was terminated, the Company was required to pay a termination fee equal to the net present value of the monitoring fees that would have been payable during the remaining term of the Management Services Agreement. Therefore, if the Management Services Agreement was terminated at September 30, 2017, the termination fee would have been calculated using the term ending December 31, 2026. In accordance with the Management Services Agreement, the Company did not record monitoring fees for the period from October 1, 2017 through December 15, 2017 (Predecessor). In December 2013, the Company and TPG Capital Management, L.P. executed a letter agreement reducing the portion of the monitoring fees owed to TPG Capital Management, L.P. by $1,325,000 for fiscal 2014 and thereafter on an annual basis by $800,000. Afshin Mohebbi was a Director of Avaya Holdings and Avaya Inc. and held the position of Senior Advisor of TPG. Ronald A. Rittenmeyer was a Director of Avaya Holdings and Avaya Inc. and served in these capacities as a director designated by TPG. The Company agreed to pay Messrs. Mohebbi and Rittenmeyer in aggregate $800,000 annually. This Management Services Agreement and consulting services were terminated upon emergence from bankruptcy. Transactions with Other Predecessor Sponsor Portfolio Companies The Predecessor Sponsors were private equity firms that had investments in companies that did business with the Company. For the period from October 1, 2017 through December 15, 2017, the Company recorded $10 million associated with sales of the Company’s products and services to companies in which one or both of the Predecessor Sponsors had investments. For the period from October 1, 2017 through December 15, 2017, the Company purchased goods and services of $15 million from companies in which one or both of the Predecessor Sponsors had investments. In September 2015, a company in which a Predecessor Sponsor had an investment merged with a commercial real estate services firm that began providing management services associated with the Company’s leased properties. Included in the above purchased goods and services amounts was $5 million incurred by the Company for management services provided by the commercial real estate services firm for the period from October 1, 2017 through December 15, 2017. Arrangements Involving the Predecessor Company’s Directors and Executive Officers In connection with the Merger, Avaya Holdings entered into a senior manager registration and preemptive rights agreement with certain members of its senior management who owned shares of Avaya Holdings’ common stock and options and RSUs convertible into shares of Avaya Holdings’ common stock. Pursuant to the senior manager registration and preemptive rights agreement, the senior managers party thereto that held registrable securities thereunder were provided with certain registration rights upon either (a) the exercise of the Predecessor Sponsors or their affiliates of demand registration rights under the Predecessor Sponsors’ registration rights agreement discussed above or (b) any request by the Predecessor Sponsors to file a shelf registration statement for the resale of such shares, as well as certain notification and piggyback registration rights. Avaya Holdings was required to bear the registration expenses, other than underwriting discounts and commissions and transfer taxes, if any, associated with any registration of stock by the senior managers as described above. Avaya Holdings had agreed to indemnify each holder of registrable securities covered by the agreement for violations of federal or state securities laws by Avaya Holdings in connection with any registration statement, prospectus or any preliminary prospectus. Each holder of such registrable securities had in turn agreed to indemnify Avaya Holdings for federal or state securities law violations that occurred in reliance upon written information the holder provided to Avaya Holdings in connection with any registration statement in which a holder of such registrable securities was participating. In addition, pursuant to the senior manager registration and preemptive rights agreement, the Company agreed to provide each senior manager party thereto with certain preemptive rights to participate in any future issuance of shares of Avaya Holdings’ common stock to the Predecessor Sponsors or their affiliates. In connection with the Merger, Avaya Holdings also entered into a management stockholders’ agreement with certain management stockholders. The stockholders’ agreement contained certain restrictions on such stockholders’ transfer of Avaya Holdings equity securities, contained rights of first refusal upon disposition of shares, contained standard tag-along and drag-along provisions, and generally set forth the respective rights and obligations of the stockholders who were parties to the agreement.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings In the ordinary course of business, the Company is involved in litigation, claims, government inquiries, investigations and proceedings, including but not limited to, those relating to intellectual property, commercial, employment, environmental indemnity and regulatory matters. The Company records accruals for legal contingencies to the extent that it has concluded that it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. In the opinion of the Company's management, while the outcome of these matters is uncertain, the likely results of these matters are not expected, either individually or in the aggregate, to have a material adverse effect on the Company's financial position, results of operations or cash flows. However, an unfavorable resolution could have a material adverse effect on the Company's financial position, results of operations or cash flows in the periods in which the matters are ultimately resolved, or in the periods in which more information is obtained that changes management's opinion of the ultimate disposition. During fiscal 2020 and 2019 (Successor) and the period from December 16, 2017 through September 30, 2018 (Successor), there were no costs incurred in connection with the resolution of legal matters other than those incurred in the ordinary course of business. During the period from October 1, 2017 through December 15, 2017 (Predecessor), costs incurred in connection with the resolution of certain legal matters were $37 million. Product Warranties The Company recognizes a liability for the estimated costs that may be incurred to remedy certain deficiencies of quality or performance of the Company’s products. These product warranties extend over a specified period of time, generally ranging up to two years from the date of sale depending upon the product subject to the warranty. The Company accrues a provision for estimated future warranty costs based upon the historical relationship of warranty claims to sales. The Company periodically reviews the adequacy of its product warranties and adjusts, if necessary, the warranty percentage and accrued warranty reserve, which is included in other current and non-current liabilities in the Consolidated Balance Sheets, for actual experience. As of September 30, 2020 and 2019, the amount reserved for product warranties was $2 million. For fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), product warranty expense recorded in the Consolidated Statements of Operations was $4 million, $3 million, $2 million and $1 million, respectively. Guarantees of Indebtedness and Other Off-Balance Sheet Arrangements Letters of Credit and Guarantees The Company provides guarantees, letters of credit and surety bonds to various parties as required for certain transactions initiated during the ordinary course of business to guarantee the Company's performance in accordance with contractual or legal obligations. As of September 30, 2020, the maximum potential payment obligation with regards to letters of credit, guarantees and surety bonds was $52 million. The outstanding letters of credit are collateralized by restricted cash of $4 million which is included in Other assets on the Consolidated Balance Sheets as of September 30, 2020. Purchase Commitments and Termination Fees The Company purchases components from a variety of suppliers and uses several contract manufacturers to provide manufacturing services for its products. During the normal course of business, to manage manufacturing lead times and to help assure adequate component supply, the Company enters into agreements with contract manufacturers and suppliers that allow them to produce and procure inventory based upon forecasted requirements provided by the Company. If the Company does not meet these specified purchase commitments, it could be required to purchase the inventory, or in the case of certain agreements, pay an early termination fee. Historically, the Company has not been required to pay a charge for not meeting its designated purchase commitments with these suppliers, but has been obligated to purchase certain excess inventory levels from its outsourced manufacturers due to actual sales of product varying from forecast and due to transition of manufacturing from one vendor to another. The Company’s outsourcing agreements with its most significant contract manufacturers automatically renew in July and September for successive periods of twelve months each, subject to specific termination rights for the Company and the contract manufacturers. All manufacturing of the Company’s products is performed in accordance with either detailed requirements or specifications and product designs furnished by the Company and is subject to quality control standards. Transactions with Nokia Pursuant to the Contribution and Distribution Agreement effective October 1, 2000 (the "Contribution and Distribution Agreement"), Nokia Corporation ("Nokia", formerly known as Lucent Technologies, Inc. ("Lucent")) contributed to the Company substantially all of the assets, liabilities and operations associated with its enterprise networking businesses (the "Contributed Businesses") and distributed the Company’s stock pro-rata to the shareholders of Lucent ("distribution"). The Contribution and Distribution Agreement, among other things, provides that, in general, the Company will indemnify Nokia for all liabilities including certain pre-distribution tax obligations of Nokia relating to the Contributed Businesses and all contingent liabilities primarily relating to the Contributed Businesses or otherwise assigned to the Company. In addition, the Contribution and Distribution Agreement provides that certain contingent liabilities not allocated to one of the parties will be shared by Nokia and the Company in prescribed percentages. The Contribution and Distribution Agreement also provides that each party will share specified portions of contingent liabilities based upon agreed percentages related to the business of the other party that exceed $50 million. The Company is unable to determine the maximum potential amount of other future payments, if any, that it could be required to make under this agreement. In addition, in connection with the distribution, the Company and Lucent entered into a Tax Sharing Agreement effective October 1, 2000 (the "Tax Sharing Agreement") that governs Nokia’s and the Company’s respective rights, responsibilities and obligations after the distribution with respect to taxes for the periods ending on or before the distribution. Generally, pre-distribution taxes or benefits that are clearly attributable to the business of one party will be borne solely by that party and other pre-distribution taxes or benefits will be shared by the parties based on a formula set forth in the Tax Sharing Agreement. The Company may be subject to additional taxes or benefits pursuant to the Tax Sharing Agreement related to future settlements of audits by state and local and foreign taxing authorities for the periods prior to the Company’s separation from Nokia.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Sep. 30, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited) The following tables present unaudited quarterly financial data. This information has been derived from the Company’s unaudited financial statements and has been prepared on the same basis as the audited Consolidated Financial Statements appearing elsewhere in this Annual Report on Form 10-K. (In millions, except per share amounts) Fourth Third Second First Fiscal year ended September 30, 2020 Revenue $ 755 $ 721 $ 682 $ 715 Gross profit 418 397 371 394 Operating income (loss) 74 53 (597) 15 Benefit from (provision for) income taxes 20 (20) (37) (25) Net income (loss) 37 9 (672) (54) Net income (loss) attributable to common stockholders 33 7 (673) (59) Earnings (loss) per common share - basic $ 0.40 $ 0.08 $ (7.24) $ (0.54) Earnings (loss) per common share - diluted $ 0.39 $ 0.08 $ (7.24) $ (0.54) (In millions, except per share amounts) Fourth Third Second First Fiscal year ended September 30, 2019 Revenue $ 723 $ 717 $ 709 $ 738 Gross profit 392 390 386 407 Operating income (loss) 52 (613) 38 50 (Provision for) benefit from income taxes (32) 27 6 (3) Net (loss) income (34) (633) (13) 9 Net (loss) income attributable to common stockholders (34) (633) (13) 9 Earnings (loss) per common share - basic $ (0.31) $ (5.70) $ (0.12) $ 0.08 Earnings (loss) per common share - diluted $ (0.31) $ (5.70) $ (0.12) $ 0.08

Condensed Financial Information

Condensed Financial Information of Parent Company	12 Months Ended
	Sep. 30, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Information of Parent Company	Condensed Financial Information of Parent Company Avaya Holdings has no material assets or stand-alone operations other than its ownership in Avaya Inc. and its subsidiaries. These condensed financial statements have been presented on a "Parent Company only" basis. Under a Parent Company only basis of presentation, the Company's investments in its consolidated subsidiaries are presented using the equity method of accounting. These Parent Company only condensed financial statements should be read in conjunction with the Company's Consolidated Financial Statements. The following presents: (1) the Successor Company, Parent Company only, statements of financial position as of September 30, 2020 and 2019, the statements of operations, comprehensive (loss) income and cash flows for the fiscal years ended September 30, 2020 and 2019 and the period from December 16, 2017 through September 30, 2018, and; (2) the Predecessor Company, Parent Company only, statements of operations, comprehensive (loss) income and cash flows for the period from October 1, 2017 through December 15, 2017. Avaya Holdings Corp. Parent Company Only Condensed Statements of Financial Position (In millions) As of September 30, 2020 2019 ASSETS Investment in Avaya Inc. $ 888 $ 1,604 TOTAL ASSETS $ 888 $ 1,604 LIABILITIES AND STOCKHOLDERS' EQUITY LIABILITIES Long-term debt $ 291 $ 273 Other liabilities 233 31 TOTAL LIABILITIES 524 304 Commitments and contingencies Convertible series A preferred stock; 125,000 shares issued and outstanding at September 30, 2020 and no shares issued and outstanding at September 30, 2019 128 — TOTAL STOCKHOLDERS' EQUITY 236 1,300 TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY $ 888 $ 1,604 Avaya Holdings Corp. Parent Company Only Condensed Statements of Operations (In millions, except per share amounts) Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from 2020 2019 Equity in net (loss) income of Avaya Inc. $ (616) $ (672) $ 311 $ 2,977 Selling, general and administrative (35) (3) — — Interest expense (26) (25) (3) — Other (expense) income, net (3) 29 (21) — (LOSS) INCOME BEFORE INCOME TAXES (680) (671) 287 2,977 Provision for income taxes — — — — NET (LOSS) INCOME (680) (671) 287 2,977 Less: Accretion and accrued dividends on Series A preferred stock (7) — — — NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS $ (687) $ (671) $ 287 $ 2,977 (LOSS) EARNINGS PER SHARE AVAILABLE TO COMMON STOCKHOLDERS Basic $ (7.45) $ (6.06) $ 2.61 $ 5.19 Diluted $ (7.45) $ (6.06) $ 2.58 $ 5.19 Weighted average shares outstanding Basic 92.2 110.8 109.9 497.3 Diluted 92.2 110.8 111.1 497.3 Avaya Holdings Corp. Parent Company Only Condensed Statements of Comprehensive (Loss) Income (In millions) Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from 2020 2019 Net (loss) income $ (680) $ (671) $ 287 $ 2,977 Equity in other comprehensive (loss) income of Avaya Inc. (72) (191) 18 658 Elimination of Predecessor Company accumulated other comprehensive loss — — — 790 Comprehensive (loss) income $ (752) $ (862) $ 305 $ 4,425 Avaya Holdings Corp. Parent Company Only Condensed Statements of Cash Flows (In millions) Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from 2020 2019 Net (loss) income $ (680) $ (671) $ 287 $ 2,977 Adjustments to reconcile net (loss) income to net cash used for operating activities: Equity in net loss (income) of Avaya Inc. 616 672 (311) (2,977) Share-based compensation 2 2 — — Amortization of debt issuance costs 18 17 4 — Change in fair value of emergence date warrants 3 (29) 17 — Changes in operating assets and liabilities — 9 3 — Net cash used for operating activities (41) — — — Net cash used for investing activities — — (314) — Net cash provided by financing activities 41 — 314 — Net increase (decrease) in cash and cash equivalents — — — — Cash and cash equivalents at beginning of period — — — — Cash and cash equivalents at end of period $ — $ — $ — $ —

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates Management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and revenue and expenses during the periods reported. Estimates and assumptions are reviewed periodically, and the effects of revisions are reflected in the Consolidated Financial Statements in the period they are determined to be necessary. Actual results could differ from these estimates. The spread of COVID-19 and the actions required to mitigate its impact have created substantial disruption to the global economy. The duration of the pandemic and the long-term impacts on the global economy are uncertain. The pandemic may affect management's estimates and assumptions, in particular those that require a projection of our financial results, our cash flows or broader economic conditions, such as the collectability of accounts receivable, sales returns and allowances, the use and recoverability of inventory, the realization of deferred tax assets, annual effective tax rate, the fair value of equity compensation, the recoverability of long-lived assets, useful lives and impairment of tangible and intangible assets including goodwill (see Note 7, "Goodwill, net"), business restructuring reserves, and fair value measurements (see Note 13, "Fair Value Measurements"). The Company also uses estimates to assess pension and post-retirement benefit costs, the fair value of assets and liabilities in connection with fresh start accounting and those acquired in business combinations, and the amount of exposure from potential loss contingencies, among others.
Principles of Consolidation	Principles of Consolidation The Consolidated Financial Statements include the accounts of Avaya Holdings Corp. and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the current year's presentation.
Acquisition Accounting	Acquisition Accounting The Company accounts for business combinations using the acquisition method, which requires an allocation of the purchase price of an acquired entity to the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. Goodwill represents the excess of the purchase price over the net tangible and intangible assets acquired.
Revenue Recognition	Revenue Recognition The Company derives revenue primarily from the sale of products and services for communications systems and applications. The Company sells directly through its worldwide sales force and indirectly through its global network of channel partners, including distributors, service providers, dealers, value-added resellers, systems integrators and business partners that provide sales and services support. On October 1, 2018, the Company adopted Accounting Standards Update ("ASU") No. 2014-09, "Revenue from Contracts with Customers (Topic 606)" ("ASC 606"). This standard superseded most of the previous revenue recognition guidance under GAAP and is intended to improve and converge with international standards the financial reporting requirements for revenue recognition. The Company adopted ASC 606 using the modified retrospective transition method applied to all open contracts with customers that were not completed as of September 30, 2018. On October 1, 2018, the Company recorded a net increase to the opening Retained earnings balance of $95 million, net of tax, due to the cumulative impact of adopting ASC 606. Under the modified retrospective method, results for reporting periods beginning after September 30, 2018 are presented under ASC 606 while prior period financial information is not adjusted and continues to be reported under prior guidance (“ASC 605”). In accordance with ASC 606, the Company accounts for a customer contract when both parties have approved the contract and are committed to perform their respective obligations, each party’s rights can be identified, payment terms can be identified, the contract has commercial substance and it is at least probable that the Company will collect the consideration to which it is entitled. The Company accrues a provision for estimated sales returns and other allowances, including promotional marketing programs and other incentives, as a reduction of revenue at the time of sale. When estimating returns, the Company considers customary inventory levels held by third-party distributors. Revenue is recognized upon the transfer of control of the promised products and services to customers. Judgment is required in instances where the Company’s contracts include multiple products and services to determine whether each should be accounted for as a separate performance obligation. The Company enters into contracts that include various combinations of products and services, each of which is generally capable of being distinct as well as distinct within the context of the contracts. Customer contracts are typically made pursuant to purchase orders and statements of work based on master purchase or partner agreements. Invoicing typically occurs upon customer acceptance or monthly for a series of services. Payment is due based on the Company’s standard payment terms which are typically within 30 to 60 days of invoice issuance. The Company does not typically provide financing arrangements to customers. For certain services and customer types, customers will remit payment before the services are provided. In instances where the timing of revenue recognition differs from the timing of invoicing, the Company determined that contracts do not include a significant financing component. The primary purpose of the invoicing terms is to provide customers with simplified and predictable ways of purchasing products and services, not to receive financing from or to provide financing to customers. Certain contracts include performance obligations accounted for as a series which also include variable consideration (primarily usage-based fees). For these arrangements, variable consideration is not estimated and allocated to the entire performance obligation, rather the variable fees are recognized in the period in which the usage occurs in accordance with the "right to invoice" practical expedient. The total transaction price for each contract is determined based on the total consideration specified in the contract, including variable consideration such as sales incentives and other discounts. The expected value method is generally used when estimating variable consideration, which typically reduces the total transaction price due to the nature of the elements to which the variable consideration relates. These estimates reflect the Company’s historical experience, current contractual requirements, specific known market events and trends, industry data and forecasted customer buying patterns. The Company excludes from the transaction price all taxes assessed by governmental authorities that are both (i) imposed on and concurrent with a specific revenue-producing transaction and (ii) collected from customers. Accordingly, such tax amounts are not included as a component of net sales or cost of sales. The expected value method requires judgment and considers multiple factors that may vary over time depending upon the unique facts and circumstances related to each performance obligation. Depending on the facts and circumstances, a change in variable consideration estimate will either be accounted for at the contract level or using the portfolio method. Reserves for contractual stock rotation rights to channel partners to support the management of inventory and certain other sales incentives are determined using the portfolio method. The Company also considers the customers’ rights of return in determining the transaction price where applicable. The Company allocates the transaction price to each performance obligation based on its relative standalone selling price and recognizes revenue as each performance obligation is satisfied. Judgment is required to determine the standalone selling price for each distinct performance obligation. The Company uses a range of selling prices to estimate standalone selling price when each of the products and services is sold separately. The Company typically has more than one standalone selling price for individual products and services due to the stratification of those products and services by customers and circumstances. In these instances, the Company may use information such as the size of the customer and geographic region in determining the standalone selling price. In instances where standalone selling price is not directly observable, such as when the Company does not sell the product or service separately, the Company determines the standalone selling price using information that may include market conditions and other observable inputs. Amounts billed to customers for shipping and handling activities are considered contract fulfillment activities and not a separate performance obligation of the contract. Shipping and handling fees are recorded as revenue and the related cost is a cost to fulfill the contract. Contract modifications are accounted for as separate contracts if the additional products and services are distinct and priced at standalone selling prices. If the additional products and services are distinct, but not priced at standalone selling prices, the modification is treated as a termination of the existing contract and the creation of a new contract. Lastly, if the additional products and services are not distinct within the context of the contract, the modification is combined with the original contract and either an increase or decrease in revenue is recognized on the modification date. The Company records a contract asset when revenue is recognized in advance of the right to bill, pursuant to customer contract terms. The contract asset decreases when the Company has the right to bill the customer which is generally triggered by the satisfaction of additional performance obligations or contract milestones. The Company records a contract liability when payment is received from the customer in advance of the Company satisfying a performance obligation and the contract liability is reduced as performance obligations are satisfied and revenue is recognized. The Company records the net contract asset or liability position for each customer contract. Software The Company’s software licenses provide users with access to capabilities such as voice, video, conferencing, messaging and collaboration. The Company’s software licenses also add functionality to the Company’s hardware. The Company’s software licenses for on-premise customer software provide the customer with a right to use the software as it exists when it is made available to the customer and are accounted for as distinct performance obligations. The Company’s software licenses are sold through both direct and indirect channels with terms that are either perpetual or time based, both of which provide the end-user with the same functionality. The main difference between perpetual and term licenses is the duration over which the customer benefits from the software. Revenue from on-premise customer software licenses is generally recognized at the point-in-time the software is made available to the customer, via direct sale to the end-user or indirect sale to a channel partner, based on the fixed minimum revenue commitment under the arrangement. However, revenue is not recognized before the beginning of the period during which the customer can use and benefit from the license. In instances where the Company’s software licenses include a usage-based fee, revenue associated with the incremental usage is recognized at the point-in-time the incremental usage occurs. The Company also sells its software under its subscription-based offerings which mainly consist of term software license arrangements and software as a service ("SaaS") arrangements. Term software licenses include multiple performance obligations where the term licenses are recognized at the point-in-time of transfer of control of the software, with the associated software maintenance revenue recognized ratably over the contract term as the customer consumes the services. SaaS arrangements do not include the right for the customer to take possession of the software during the contractual term of the arrangement, and therefore have one distinct performance obligation which is satisfied over time with revenue recognized ratably over the contract term as the customer consumes the services. Subscription-based offerings typically have terms that range from one to five years. ACO Avaya Cloud Office by RingCentral or “ACO”, was introduced by the Company to accelerate the Company's transition to the cloud. Through this partnership, ACO combines RingCentral's UCaaS platform with Avaya technology, services and migration capabilities to create a differentiated UCaaS offering. These services are accounted for as two distinct performance obligations, one being a licensing component that is generally recognized at the point-in-time the software is made available to the customer, and the second being associated support services which represents a stand-ready obligation whereby the revenues are generally recognized ratably over the contract term. The Company’s ACO solution is provided through both direct and indirect channels. Contracts typically have terms that range from one to five years. Hardware The Company’s hardware, phones, gateways, and servers, each of which has a stand-alone functionality, are generally considered distinct performance obligations. Hardware is sold through both direct and indirect channels and revenue is recognized at the point-in-time at which control of the product is transferred to the customer, via direct sale to the end-user or indirect sale to a channel partner, generally upon delivery, as defined in the contract. Global Support Services The Company’s global support services provide supplemental maintenance options to end-users in support of the Company’s products and solutions, including when and if available upgrade rights and maintenance for hardware. These services are typically accounted for as distinct performance obligations. Given that global support services consist of a series of distinct promises that are satisfied over time in the form of a single performance obligation comprised of a stand-ready obligation, these services are generally recognized ratably over the period during which the services are performed as customers simultaneously consume and receive benefits. Maintenance contracts typically have terms that range from one to five years. Professional Services The Company’s professional services include the design, implementation and development of communication solutions. Professional services are sold through the Company’s direct and indirect channels either on a stand-alone basis or with other hardware, software and services and are generally accounted for as distinct performance obligations. Revenue for professional services is generally recognized over time based on the cost of effort incurred to date relative to the total cost of effort expected to be incurred as customers simultaneously consume and receive benefits. Effort incurred generally represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Contracts for professional services typically have terms that range from four to six weeks for simple engagements and from six months to three years for more complex engagements. Prior to the adoption of ASC 606, revenue for professional services was recognized upon completion and acceptance of the project and when such arrangements included products, product revenue was also recognized upon completion and acceptance of the project. Cloud and Managed Services The Company’s managed services provide additional support options to end-users on top of the Company’s supplemental maintenance services, including hardware support, help-desk routing and system monitoring services. The Company’s managed services are sold either on a stand-alone basis or together with the Company’s hardware, software and other services, and are generally accounted for as distinct performance obligations. The Company’s managed services are provided through both direct and indirect channels. Managed services consist of a series of distinct promises that are satisfied over time in the form of a single performance obligation comprised of a stand-ready obligation. Contracts for managed services typically have terms that range from one to five years. The Company’s cloud offerings enable customers to take advantage of its technology via the cloud, or as a hybrid with its on-premise solutions. The software that enables the core communications functionality is offered both as a sale of perpetual or time based licenses or through a SaaS arrangement. Cloud offerings can include supplemental maintenance and managed services and are sold through the Company’s direct and indirect channels. Cloud and managed services offerings often include multiple performance obligations. Each performance obligation can itself include a series of distinct promises that are satisfied over time. Total consideration for a project is allocated to each performance obligation, with revenue recognized ratably over the period during which the services are performed as customers simultaneously consume and receive benefits. Variable consideration from incremental usage above a fixed fee is recognized at the point-in-time at which the usage occurs. Warranties The Company offers standard limited warranties that provide the customer with assurance that its products will function in accordance with contract specifications. The Company’s standard limited warranties are not sold separately but are included with each customer purchase. Warranties are not considered separate performance obligations, and therefore, warranty expense is accrued at the time the related revenue is recognized.
Cash and Cash Equivalents	Cash and Cash Equivalents All highly liquid investments with original maturities of three months or less at the date of purchase are classified as cash equivalents.
Concentrations of Risk	Concentrations of Risk The Company’s cash and cash equivalents are maintained with several financial institutions. Deposits held at banks may exceed the amount of insurance provided on such deposits. Generally, these deposits may be redeemed upon demand and are maintained with financial institutions with reputable credit and therefore bear minimal credit risk. The Company seeks to mitigate such risks by spreading its risk across multiple counterparties and monitoring the risk profiles of these counterparties. The Company, from time to time, may enter into derivative financial instruments with high credit quality financial institutions to manage foreign exchange rate and interest rate risk and is exposed to losses in the event of non-performance by the counterparties to these contracts. To date, no counterparty has failed to meet its obligations to the Company. The Company relies on a limited number of contract manufacturers and suppliers to provide manufacturing services for its products. The inability of a contract manufacturer or supplier to fulfill supply requirements of the Company could materially impact future operating results.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded when the customer has been billed or the right to consideration is unconditional. Accounts receivable are recorded net of reserves for sales returns and allowances and provisions for doubtful accounts. The Company performs ongoing credit evaluations of its customers and generally does not require collateral from its customers. The allowances are based on analyses of historical trends, aging of accounts receivable balances and the creditworthiness of customers as determined by credit checks, analyses and payment history. At September 30, 2020 and 2019, one distributor accounted for approximately 9% and 12% of accounts receivable.
Inventory	Inventory Inventory includes goods awaiting sale (finished goods) and goods to be used in connection with providing maintenance services. Inventory is stated at the lower of cost or net realizable value, determined on a first-in, first-out method. Reserves to reduce the inventory cost to net realizable value are based on current inventory levels, assumptions about future demand and product life cycles for the various inventory types.
Research and Development Costs	Research and Development Costs Research and development costs are charged to expense as incurred. The costs incurred for the development of communications software that will be sold, leased or otherwise marketed, however, are capitalized when technological feasibility has been established in accordance with FASB ASC Topic 985, "Software" ("ASC 985"). The Company has continued to leverage agile development methodologies, which are characterized by a more dynamic development process with more frequent revisions to a product releases' features and functions as the software is being developed with technological feasibility being met shortly before the product revision is made generally available. As such, no amounts were capitalized for internally developed software costs in the Company's Consolidated Financial Statements during fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor).
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are stated at cost less accumulated depreciation. Depreciation is determined using the straight-line method over the estimated useful lives of the assets. Estimated lives range from 2 to 10 years for machinery and equipment and the remaining lease term for equipment acquired under a financing lease. Improvements that extend the useful life of assets are capitalized and maintenance and repairs are charged to expense as incurred. Capitalized improvements to facilities subject to operating leases are depreciated over the lesser of the estimated useful life of the asset or the duration of the lease. Upon retirement or disposal of assets, the cost and related accumulated depreciation are removed from the Consolidated Balance Sheets and any gain or loss is reflected in the Consolidated Statements of Operations.
Internal Use Software	The Company capitalizes costs associated with software developed or obtained for internal use when the preliminary project stage is completed and it is determined that the software will provide enhanced capabilities. Internal use software is amortized on a straight-line basis generally over 5 to 7 years. Costs capitalized include payroll and related benefits, third party development fees and acquired software and licenses. General and administrative costs, overhead, maintenance and training, and the cost of the software that does not add functionality to existing systems, are expensed as incurred. The Company had unamortized internal use software costs included in Property, Plant and Equipment, net in the Consolidated Balance Sheets of $91 million and $83 million as of September 30, 2020 and 2019, respectively. Depreciation expense related to internal use software recognized in the Consolidated Statements of Operations for fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor) was $27 million, $39 million, $31 million and $5 million, respectively.
Goodwill	Goodwill Goodwill is not amortized but is subject to periodic testing for impairment in accordance with FASB ASC Topic 350, "Intangibles-Goodwill and Other" ("ASC 350") at the reporting unit level. The Company's reporting units are subject to impairment testing annually, on July 1 st , or more frequently if events occur or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. The Company's goodwill was primarily recorded upon emergence from bankruptcy as a result of applying fresh start accounting. ASC 350 provides the option to assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. The Company has the unconditional option to bypass the qualitative assessment for any reporting unit in any period and proceed directly to performing a quantitative goodwill impairment test. If the assessment of all relevant qualitative factors indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, a quantitative goodwill impairment test is not necessary. If the assessment of all relevant qualitative factors indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the Company will perform a quantitative goodwill impairment test. The quantitative impairment test for goodwill consists of a comparison of the fair value of a reporting unit with its carrying value, including the goodwill allocated to that reporting unit. If the carrying value of a reporting unit exceeds its fair value, the Company will recognize an impairment loss equal to the amount of the excess, limited to the amount of goodwill allocated to that reporting unit. Application of the impairment test requires judgement, including the identification of reporting units, assignment of assets and liabilities to reporting units and the determination of fair value of each reporting unit. In performing the quantitative goodwill impairment test, the Company estimates the fair value of each reporting unit using a weighting of fair values derived from an income approach and a market approach. Under the income approach, the fair value of a reporting unit is estimated using a discounted cash flows model. Future cash flows are based on forward-looking information regarding revenue and costs for each reporting unit and are discounted using an appropriate discount rate. The discounted cash flows model relies on assumptions regarding revenue growth rates, projected gross profit, working capital needs, selling, general and administrative expenses, research and development expenses, business restructuring costs, capital expenditures, income tax rates, discount rates and terminal growth rates. The discount rates the Company uses represent the estimated weighted average cost of capital, which reflects the overall level of inherent risk involved in its reporting unit operations and the rate of return an outside investor would expect to earn. To estimate cash flows beyond the final year of its model, the Company uses a terminal value approach. Under this approach, the Company applies a perpetuity growth assumption to determine the terminal value. The Company incorporates the present value of the resulting terminal value into its estimate of fair value. Forecasted cash flows for each reporting unit consider current economic conditions and trends, estimated future operating results, the Company's view of growth rates and anticipated future economic conditions. Revenue growth rates inherent in the forecasts are based on input from internal and external market intelligence research sources that compare factors such as growth in global economies, regional trends in the telecommunications industry and product evolution. Macroeconomic factors such as changes in economies, product evolution, industry consolidation and other changes beyond the Company's control could have a positive or negative impact on achieving its targets. The market approach estimates the fair value of a reporting unit by applying multiples of operating performance measures to the reporting unit's operating performance (the "Guideline Public Company Method"). These multiples are derived from comparable publicly-traded companies with similar investment characteristics to the reporting unit. The key estimates and assumptions that are used to determine the fair value under the market approach include current and projected 12-month operating performance results, as applicable, and the selection of the relevant multiples that are applied.
Financial Instruments	Derivative Financial Instruments
Restructuring Programs	Restructuring Programs A business restructuring is defined as an exit or disposal activity that includes, but is not limited to, a program that is planned and controlled by management and materially changes either the scope of a business or the manner in which that business is conducted. The Company's business restructuring charges include (i) one-time termination benefits related to employee separations, (ii) contract termination costs and (iii) other related costs associated with exit or disposal activities including, but not limited to, costs for consolidating or closing facilities and relocating employees. The Company accounts for non-facility related exit or disposal activities in accordance with FASB ASC Topic 420, "Exit or Disposal Cost Obligations" ("ASC 420"). A liability is recognized and measured at its fair value for one-time termination benefits once the plan of termination meets all of the following criteria: (i) management commits to a plan of termination, (ii) the plan identifies the number of employees to be terminated and their job classifications or functions, locations and the expected completion date, (iii) the plan establishes the terms of the benefit arrangement and (iv) it is unlikely that significant changes to the plan will be made or the plan will be withdrawn. Contract termination costs include costs to terminate a contract or costs that will continue to be incurred under the contract without benefit to the Company. A liability is recognized and measured at its fair value when the Company either terminates the contract or ceases using the rights conveyed by the contract. A liability is recognized and measured at its fair value for other related costs in the period in which the liability is incurred. As of October 1, 2019, the Company accounts for facility-related exit or disposal activities in accordance with ASC 842 and no longer records facility-related restructuring charges within the Business restructuring reserve on the Consolidated Balance Sheets. The adoption of ASC 842 resulted in a one-time reclassification of $5 million for certain facility-related lease obligations from the Business restructuring reserve to Operating lease right-of-use assets. Facility exit costs primarily include lease obligation charges for exited facilities, including the impact of accelerated lease expense for right-of-use assets and accelerated depreciation expense for leasehold improvements with reductions in their estimated useful lives due to exited facilities. The Company’s accounting for such charges is dependent on whether it has the ability and intent to sublease an exited facility. In circumstances in which the Company has the ability and intent to sublease an exited facility, the Company performs an impairment test of the asset group by comparing its fair value to its carrying value on the earlier of the sublease inception date or cease use date. To the extent the carrying value of the asset group is greater than its fair value, an impairment charge is recorded within the Restructuring charges line item in the Company's Consolidated Statements of Operations. If the Company does not have the ability and intent to sublease an exited facility, the Company adjusts the estimated useful life of the facility related assets to end on the cease use date and recognizes accelerated depreciation and amortization within the Restructuring charges line item in the Consolidated Statements of Operations. The amortization of right-of-use assets for exited facilities is recorded within Restructuring charges after the cease use date. Sublease income is recorded within Other income, net in the Consolidated Statements of Operations. Pension and Post-retirement Benefit Obligations
Pension and Postretirement Benefit Obligations	The Company sponsors non-contributory defined benefit pension plans covering a portion of its U.S. employees and retirees, and post-retirement benefit plans covering a portion of its U.S. employees and retirees that include healthcare benefits and life insurance coverage. Certain non-U.S. operations have various retirement benefit programs covering substantially all of their employees. Some of these programs are considered to be defined benefit pension plans for accounting purposes. These pension and other post-retirement benefits are accounted for in accordance with FASB ASC Topic 715, "Compensation—Retirement Benefits" ("ASC 715"). ASC 715 requires that plan assets and obligations be measured as of the reporting date and the over-funded, under-funded or unfunded status of plans be recognized as of the reporting date as an asset or liability in the Consolidated Balance Sheets. In addition, ASC 715 requires costs and related obligations and assets arising from pensions and other post-retirement benefit plans to be accounted for based on actuarially determined estimates. The Company’s pension and post-retirement benefit costs are developed from actuarial valuations. Inherent in these valuations are key assumptions, including the discount rate and expected long-term rate of return on plan assets. Material changes in pension and post-retirement benefit costs may occur in the future due to changes in these assumptions, in the number of plan participants, in the level of benefits provided, in asset levels and in legislation. The market-related value of the Company’s plan assets as of the measurement date is developed using a five-year smoothing technique. First, a preliminary market-related value is calculated by adjusting the market-related value at the beginning of the year for payments to and from plan assets and the expected return on assets during the year. The expected return on assets represents the expected long-term rate of return on plan assets adjusted up to plus or minus 2% based on the actual ten-year average rate of return on plan assets. A final market-related value is determined as the preliminary market-related value, plus 20% of the difference between the actual return and expected return for each of the past five years. The plans use different factors based on plan provisions and participant census data, including years of service, eligible compensation and age, to determine the benefit amount for eligible participants. The Company funds its U.S. pension plans in compliance with applicable laws.
Advertising Costs	Advertising CostsThe Company expenses advertising costs as incurred. Advertising costs were $42 million, $39 million, $27 million and $9 million for fiscal 2020 and 2019 (Successor), the period from December 16, 2017 through September 30, 2018 (Successor) and the period from October 1, 2017 through December 15, 2017 (Predecessor), respectively.
Share-based Compensation	Share-based Compensation The Company accounts for share-based compensation in accordance with FASB Topic ASC 718, "Compensation-Stock Compensation," which requires the measurement and recognition of compensation expense for all share-based payment awards made to employees and non-employee directors including stock options, restricted stock, restricted stock units, performance awards and other forms of awards granted or denominated in shares of the Company’s common stock, as well as certain cash-based awards. Upon emergence from bankruptcy, the Company changed its accounting policy related to determining the fair value of certain equity awards. Prior to the Emergence Date, the Predecessor Company used the Cox-Ross-Rubenstein ("CRR") binomial option pricing model to determine the grant date fair values of stock options and its Preferred Series A and B Stock
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the Consolidated Statements of Operations in the period that includes the enactment date. A valuation allowance is recorded to reduce the carrying amounts of deferred tax assets if it is more likely than not that such assets will not be realized. Additionally, the accounting for income taxes requires the Company to evaluate and make an assertion as to whether undistributed foreign earnings will be indefinitely reinvested or repatriated. FASB ASC Subtopic 740-10, "Income Taxes—Overall" ("ASC 740-10") prescribes a comprehensive model for the financial statement recognition, measurement, classification, and disclosure of uncertain tax positions. ASC 740-10 contains a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, based on the technical merits of the position. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. Significant judgment is required in evaluating uncertain tax positions and determining the provision for income taxes. Although the Company believes its reserves are reasonable, no assurance can be given that the final tax outcome of these matters will not be different from that which is reflected in the historical income tax provision and accruals. The Company adjusts its estimated liability for uncertain tax positions periodically due to new information discovered from ongoing examinations by, and settlements with, various taxing authorities, as well as changes in tax laws, regulations and interpretations. The Company's policy is to recognize, when applicable, interest and penalties on uncertain tax positions as part of income tax expense. As part of the Company's accounting for business combinations, some of the purchase price is allocated to goodwill and intangible assets. Impairment expenses associated with goodwill are generally not tax deductible and will result in an increased effective income tax rate in the fiscal period any impairment is recorded. The income tax benefit from future releases of the acquisition date valuation allowances or income tax contingencies, if any, are reflected in the income tax provision in the Consolidated Statements of Operations, rather than as an adjustment to the purchase price allocation.
Net Income (Loss) Per Share	(Loss) Earnings Per Share The Company uses the two-class method to calculate basic and diluted (loss) earnings per share as its Series A Preferred Stock are participating securities. Under the two-class method, undistributed earnings are allocated to common stock and participating securities according to their respective participating rights in undistributed earnings, as if all the earnings for the period had been distributed. Basic (loss) earnings per common share is computed by dividing the net (loss) income attributable to common stockholders by the weighted average number of common shares outstanding during the period. Net (loss) income attributable to common stockholders is reduced for preferred stock dividends earned and accretion recognized during the period. No allocation of undistributed earnings to preferred shares is performed for periods with net losses as such securities do not have a contractual obligation to share in the losses of the Company. Diluted (loss) earnings per share is computed by dividing the net (loss) income attributable to common stockholders by the weighted average number of common shares outstanding plus potentially dilutive common shares.
Deferred Financing Costs	Deferred Financing Costs Deferred financing costs are amortized using the effective interest method as interest expense over the contractual lives of the related credit facilities. Deferred financing costs related to a debt liability are presented on the Consolidated Balance Sheets as a reduction of the carrying amount of that debt liability and deferred financing costs related to revolving credit facilities are included within other assets.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities of non-U.S. subsidiaries that operate in a local currency environment, where the local currency is the functional currency, are translated from foreign currencies into U.S. dollars at period-end exchange rates. Upon emergence from bankruptcy, the Company changed its accounting policy related to translating the income and expense of non-U.S. dollar functional currency subsidiaries into U.S. dollars. Prior to the Emergence Date, the Predecessor Company translated the income and expense of non-U.S. dollar functional currency subsidiaries into U.S. dollars at the spot rate for the transaction. Subsequent to the Emergence Date, the Successor Company translates the income and expense of non-U.S. dollar functional currency subsidiaries into U.S. dollars using an average rate for the period. Translation gains or losses related to net assets located outside the U.S. are shown as a component of Accumulated other comprehensive (loss) in the Consolidated Balance Sheets. Gains and losses resulting from foreign currency transactions, which are denominated in currencies other than the functional currency, are included in Other income (expense), net in the Consolidated Statements of Operations.
Other Comprehensive Income (Loss)	.
Revenue from Contract with Customer	Contract Assets The Company recognizes a contract asset when it transfers products and services to a customer in advance of scheduled billings. Contract assets decrease when the Company invoices the customer or the right to receive consideration is unconditional. Contract Costs
Lessee, Leases	Leases On October 1, 2019, the Company adopted ASU No. 2016-02, "Leases (Topic 842)." This standard, along with other guidance subsequently issued by the FASB (collectively "ASC 842"), superseded all lease accounting guidance and requires lessees to recognize lease assets and liabilities for all leases with initial lease terms of more than 12 months. The Company adopted ASC 842 using the modified retrospective transition method as of the beginning of the period of adoption. Therefore, on October 1, 2019, the Company recognized and measured leases without revising the historical comparative period information or disclosures. See Note 3, “Recent Accounting Pronouncements” for additional information related to the adoption of ASC 842. The Company enters into various arrangements for office, warehouse and data center facilities, network equipment and vehicles. In accordance with ASC 842, the Company assesses whether an arrangement contains a lease at contract inception. When an arrangement contains a lease, the Company records a right-of-use asset and lease liability. Right-of-use assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make payments for the right to use the asset.
Intangible Assets, Finite-Lived, Policy	Intangible and Long-lived Assets Intangible assets include technology and patents, customer relationships and trademarks and trade names. Intangible assets with finite lives are amortized using the straight-line method over the estimated economic lives of the assets, which range from 1 to 19 years. Long-lived assets, including intangible assets with finite lives, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable in accordance with FASB ASC Topic 360, "Property, Plant, and Equipment." Intangible assets determined to have indefinite useful lives are not amortized but are tested for impairment annually, on July 1st, or more frequently if events occur or circumstances change that indicate an asset may be impaired. The recoverability test of finite-lived assets is based on forecasts of undiscounted cash flows for each asset group. The impairment test of the Company’s indefinite-lived intangible asset, the Avaya Trade Name consists of a comparison of the estimated fair value of the asset with its carrying value. If the carrying value of the Avaya Trade Name exceeds its estimated fair value, the Company will recognize an impairment loss equal to the amount of the excess. The fair value of the Avaya Trade Name is estimated using the relief-from-royalty model, a form of the income approach. Under this methodology, the fair value of the trade name is estimated by applying a royalty rate to forecasted net revenues which is then discounted using a risk-adjusted rate of return on capital. Revenue growth rates inherent in the forecast are based on input from internal and external market intelligence research sources that compare factors such as growth in global economies, regional trends in the telecommunications industry and product evolution. The royalty rate is determined using a set of observed market royalty rates. The estimated useful lives of intangible and long-lived assets are based on many factors including assumptions regarding the effects of obsolescence, demand, competition and other economic factors, expectations regarding the future use of the asset, and the Company's historical experience with similar assets. The assumptions used to determine the estimated useful lives could change due to numerous factors including product demand, market conditions, technological developments, economic conditions and competition. Amortizable technology and patents have useful lives that range between 1 and 10 years with a weighted average remaining useful life of 3.1 years. Customer relationships have useful lives that range between 1 and 19 years with a weighted average remaining useful life of 11.9 years. Amortizable product trade names have useful lives of 10 years with a weighted average remaining useful life of 7.2 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.

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	12 Months Ended
	Sep. 30, 2020
Accounting Changes and Error Corrections [Abstract]
Accounting Standards Update and Change in Accounting Principle	The impact of the adoption of ASC 842 on the September 30, 2019 Consolidated Balance Sheet was as follows: September 30, 2019 Upon Adoption of ASC 842 (In millions) As Reported Adjustments ASSETS Other current assets $ 115 $ (2) $ 113 Intangible assets, net 2,891 (2) 2,889 Operating lease right-of-use assets — 190 190 LIABILITIES Current liabilities: Operating lease liabilities — 51 51 Business restructuring reserve 33 (4) 29 Non-current liabilities: Operating lease liabilities — 143 143 Business restructuring reserve 36 (1) 35 Other liabilities 316 (3) 313

Fresh Start Accounting (Tables)

Fresh Start Accounting (Tables)	12 Months Ended
	Sep. 30, 2020
Reorganizations [Abstract]
Schedule of Fresh-Start Adjustments	The following table reconciles the enterprise value to the estimated fair value of the Successor stockholders' equity as of the Emergence Date: (In millions, except per share amount) Enterprise value $ 5,721 Plus: Cash and cash equivalents 366 Less: Minimum cash required for operations (120) Fair value of Term Loan Credit Agreement (1) (2,896) Fair value of capitalized leases (20) Fair value of pension and other post-retirement obligations, net of tax (2) (856) Change in net deferred tax liabilities from reorganization (510) Fair value of Successor Emergence Date Warrants (3) (17) Fair value of Successor common stock $ 1,668 Shares issued at December 15, 2017 upon emergence 110.0 Successor common stock value per share $ 15.16 (1) The fair value of the Term Loan Credit Agreement was determined based on a market approach utilizing market-clearing data on the valuation date in addition to bid/ask prices and was estimated to be 99% of par value. (2) The following assumptions were used when measuring the fair value of the U.S. pension, non-U.S. pension, and post-retirement benefit plans: weighted-average return on assets of 7.75%, 3.80% and 5.90%, and weighted-average discount rate to measure plan obligations of 3.70%, 1.52% and 3.77%, respectively. (3) The fair value of the Emergence Date Warrants was estimated using the Black-Scholes pricing model. The following table reconciles the enterprise value to the estimated reorganization value as of the Emergence Date: (In millions) Enterprise value $ 5,721 Plus: Non-debt current liabilities 955 Non-debt non-current liabilities 2,090 Excess cash and cash equivalents 246 Less: Pension and other post-retirement obligations, net of deferred taxes (856) Capital lease obligations (20) Change in net deferred tax liabilities from reorganization (510) Emergence Date Warrants issued (17) Reorganization value of Successor assets $ 7,609 (In millions) Predecessor Company Reorganization Adjustments Fresh Start Adjustments Successor Company ASSETS Current assets: Cash and cash equivalents $ 770 $ (404) (1) $ — $ 366 Accounts receivable, net 497 — (106) (21) 391 Inventory 90 — 29 (22) 119 Other current assets 374 (58) (2) (66) (23) 250 TOTAL CURRENT ASSETS 1,731 (462) (143) 1,126 Property, plant and equipment, net 194 — 116 (24) 310 Deferred income taxes, net — 48 (3) (17) (25) 31 Intangible assets, net 298 — 3,137 (26) 3,435 Goodwill 3,541 — (883) (27) 2,658 Other assets 70 6 (4) (27) (28) 49 TOTAL ASSETS $ 5,834 $ (408) $ 2,183 $ 7,609 LIABILITIES Current liabilities: Debt maturing within one year $ 725 $ (696) (5) $ — $ 29 Accounts payable 325 (49) (6) — 276 Payroll and benefit obligations 123 23 (7) — 146 Deferred revenue 627 50 (8) (341) (29) 336 Business restructuring reserve 35 3 (9) — 38 Other current liabilities 97 65 (6,10) (3) (30) 159 TOTAL CURRENT LIABILITIES 1,932 (604) (344) 984 Non-current liabilities: Long-term debt, net of current portion — 2,771 (11) 96 (31) 2,867 Pension obligations 539 246 (12) — 785 Other post-retirement obligations — 212 (13) — 212 Deferred income taxes, net 28 113 (14) 548 (32) 689 Business restructuring reserve 26 4 (9) 4 (33) 34 Other liabilities 180 233 (8,15) (43) (29,34) 370 TOTAL NON-CURRENT LIABILITIES 773 3,579 605 4,957 LIABILITIES SUBJECT TO COMPROMISE 7,585 (7,585) (16) — — TOTAL LIABILITIES 10,290 (4,610) 261 5,941 Commitments and contingencies Equity awards on redeemable shares 6 (6) (17) — — Preferred stock: Series B 397 (397) (17) — — Series A 186 (186) (17) — — STOCKHOLDERS' (DEFICIT) EQUITY Common stock (Successor) — 1 (18) — 1 Additional paid-in capital (Successor) — 1,667 (18) — 1,667 Common stock (Predecessor) — — — — Additional paid-in capital (Predecessor) 2,387 (2,387) (17) — — (Accumulated deficit) retained earnings (5,978) 4,846 (19) 1,132 (36) — Accumulated other comprehensive (loss) income (1,454) 664 (20) 790 (35) — TOTAL STOCKHOLDERS' (DEFICIT) EQUITY (5,045) 4,791 1,922 1,668 TOTAL LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY $ 5,834 $ (408) $ 2,183 $ 7,609 Reorganization Adjustments In accordance with the Plan of Reorganization, the following adjustments were made: 1. Sources and Uses of Cash. The following reflects the net cash payments recorded as of the Emergence Date as a result of implementing the Plan of Reorganization: (In millions) Sources: Proceeds from Term Loan Credit Agreement, net of original issue discount $ 2,896 Release of restricted cash 76 Total sources of cash 2,972 Uses: Repayment of DIP Credit Agreement (725) Payment of DIP Credit Agreement accrued interest (1) Cash paid to Predecessor first lien debt-holders (2,061) Cash paid to PBGC (340) Payment for professional fees escrow account (56) Funding payment for Avaya represented employee pension plan (49) Payment of accrued professional and administrative fees (27) Costs incurred for Term Loan Credit Agreement and ABL Credit Agreement (59) Payment for general unsecured claims (58) Total uses of cash (3,376) Net uses of cash $ (404) 2. Other Current Assets. (In millions) Release of restricted cash $ (76) Reclassification of prepaid debt issuance costs related to the Term Loan Credit Agreement (42) Payment of fees related to the ABL Credit Agreement 5 Restricted cash for bankruptcy related professional fees 55 Total other current assets $ (58) 3. Deferred Income Taxes. The adjustment represents the release of the valuation allowance on deferred tax assets for certain non-U.S. subsidiaries which management believes more likely than not will be realized as a result of the bankruptcy reorganization. 4. Other Assets. The adjustment represents the re-establishment of foreign prepaid taxes. 5. Debt Maturing Within One Year. The adjustment represents the net effect of the Company’s repayment of $725 million for the DIP Credit Agreement and Term Loan Credit Agreement principal payments of $29 million due over the next year. 6. Accounts Payable . The net decrease of $49 million includes $50 million for professional fees that were reclassified to Other current liabilities for accrued bankruptcy related professional fees that were paid from an escrow account and a payment of $3 million of bankruptcy related professional fees, partially offset by reinstatement of $4 million contract cure costs from liabilities subject to compromise. 7. Payroll and Benefi t Obligations. The Company reinstated $23 million of liabilities subject to compromise related to the post-employment and post-retirement benefit obligations. 8. Deferred Revenue. The reinstatement of liabilities subject to compromise was $79 million of which $50 million is included in deferred revenue and $29 million in other liabilities. 9. Business Restructuring Reserve. The reinstatement of liabilities subject to compromise was $7 million, of which $3 million is current and $4 million is non-current. 10. Other Current Liabilities. (In millions) Reclassification of accrued bankruptcy related professional fees $ 50 Reinstatement of other current liabilities 16 Payment of accrued interest on the DIP Credit Agreement (1) Total other current liabilities $ 65 11. Exit Financing. In accordance with the Plan of Reorganization, the Company entered into the Term Loan Credit Agreement with a principal amount of $2,925 million, and the ABL Credit Agreement, which allows borrowings up to an aggregate principal amount of $300 million, subject to borrowing base availability. (In millions) Term Loan Credit Agreement $ 2,925 Less: Discount (29) Upfront and underwriting fees (54) Cash received upon emergence from bankruptcy 2,842 Reclassification of debt issuance costs incurred prior to emergence from bankruptcy (42) Current portion of Long-term debt (29) Long-term debt, net of current portion $ 2,771 12. Pension Obligations. In accordance with the Plan of Reorganization, the Company reinstated from liabilities subject to compromise $295 million related to the Avaya Pension Plan for represented employees and also contributed $49 million to the related pension trust. 13. Other Post-retirement Obligations. Other post-retirement benefit obligations of $212 million were reinstated from liabilities subject to compromise. 14. Deferred Income Taxes . The adjustment represents the reinstatement of the deferred tax liability that was included in liabilities subject to compromise. 15. Other Liabilities . The increase of $233 million primarily relates to the reinstatement of employee benefits, tax liabilities and deferred revenue from liabilities subject to compromise. Also included is the value of the Emergence Date Warrants issued to the holders of the Predecessor second lien obligations. 16. Liabilities Subject to Compromise. Liabilities subject to compromise were reinstated or settled as follows in accordance with the Plan of Reorganization: (In millions) Liabilities subject to compromise $ 7,585 Less amounts settled per the Plan of Reorganization Pre-petition first lien debt (4,281) Pre-petition second lien debt (1,440) Avaya Pension Plan for Salaried Employees (620) Amounts reinstated: Accounts payable (4) Payroll and benefit obligations (23) Deferred revenue (50) Business restructuring reserves (7) Other current liabilities (16) Pension obligations (295) Other post-retirement obligations (212) Deferred income taxes, net (118) Other liabilities (216) Total liabilities reinstated at emergence (941) General unsecured credit claims (1) (303) Liabilities subject to compromise $ — (1) In settlement of allowed general unsecured claims, each claimant will receive a pro-rata distribution of $58 million of the general unsecured claims account. The following table displays the detail on the gain on settlement of liabilities subject to compromise: (In millions) Pre-petition first lien debt $ 711 Pre-petition second lien debt 1,356 Avaya pension plan for salaried employees (516) General unsecured creditors' claims 227 Net gain on settlement of Liabilities subject to compromise $ 1,778 17. Cancellation of Predecessor Preferred and Common Stock. All common stock, Series A and B preferred stock and all other equity awards of the Predecessor Company were canceled on the Emergence Date without any recovery on account thereof. 18. Issuance of Successor Common Stock and Emergence Date Warrants. In settlement of the Company's $5,721 million Predecessor first lien obligations and Predecessor second lien obligations, the holders of the Predecessor first lien obligations received a total of 99.3 million shares of common stock (fair value of $1,509 million) and $2,061 million in cash and the holders of the Predecessor second lien obligations received a total of 4.4 million shares of common stock (fair value of $67 million) and 5.6 million Emergence Date Warrants to purchase a like amount of common shares (fair value of $17 million). In addition, as part of the Plan of Reorganization, the Company completed a distressed termination of the APPSE in accordance with a stipulation settlement with the PBGC, the PBGC received $340 million in cash and 6.1 million shares of common stock (fair value of $92 million). 19. Accumulated Deficit. (In millions) Accumulated deficit: Net gain on settlement of liabilities subject to compromise $ 1,778 Expense for certain professional fees (26) Benefit from income taxes 118 Cancellation of Predecessor equity awards 6 Cancellation of Predecessor Preferred stock Series B 397 Cancellation of Predecessor Preferred stock Series A 186 Cancellation of Predecessor Common stock 2,387 Total $ 4,846 20. Accumulated Comprehensive Loss. The changes to Accumulated comprehensive loss relate to the settlement of the APPSE and the Avaya Supplemental Pension Plan ("ASPP") and the associated taxes. Fresh Start Adjustments At the Emergence Date, the Company met the requirements under ASC 852 for the adoption of fresh start accounting. These adjustments reflect actual amounts recorded as of the Emergence Date. 21. Accounts Receivable. This adjustment relates to a change in accounting policy for the way the Company will present uncollected deferred revenue upon emergence from bankruptcy. The Company offset such deferred revenue against the related account receivable. 22. Inventory . This adjustment relates to the write-up of inventory to fair value based on estimated selling prices, less costs of disposal. 23. Other Current Assets . This adjustment reflects the write-off of certain prepaid commissions, deferred installation costs and debt issuance costs that do not meet the definition of an asset upon emergence. 24. Property, Plant and Equipment . An adjustment of $116 million was recorded to increase the net book value of property, plant and equipment to its estimated fair value based on estimated current acquisition price, plus costs to make the property fully operational. (In millions) Buildings and improvements $ 82 Machinery and equipment 38 Rental equipment 85 Assets under construction 13 Internal use software 92 Total property, plant and equipment 310 Less: accumulated depreciation and amortization — Property, plant and equipment, net $ 310 25. Deferred Income Tax. T he adjustment represents the release of the valuation allowance on deferred tax assets for certain non-U.S. subsidiaries which management believes more likely than not will be realized as a result of future taxable income from the reversal of deferred tax liabilities that were established as part of fresh start accounting. 26. Intangible Assets. The Company recorded an adjustment to intangible assets for $3,137 million as follows: Successor Predecessor (In millions) December 15, 2017 Post-emergence December 15, 2017 Pre-emergence Difference Customer relationships and other intangible assets $ 2,155 $ 96 $ 2,059 Technology and patents 905 12 893 Trademarks and trade names 375 190 185 Total $ 3,435 $ 298 $ 3,137 The fair value of customer relationships was determined using the excess earnings method, a derivation of the income approach that calculates residual profit attributable to an asset after proper returns are paid to complementary or contributory assets. The fair value of technology and patents and trademarks and trade names was determined using the royalty savings method, a derivation of the income approach that estimates the royalties saved through ownership of the assets. 27. Goodwill. Predecessor Company goodwill of $3,541 million was eliminated and Successor Company goodwill of $2,658 million was established based on the calculated reorganization value. (In millions) Reorganization value of Successor Company $ 7,609 Less: Fair value of Successor Company assets (4,951) Reorganization value of Successor Company assets in excess of fair value - Goodwill $ 2,658 28. Other Assets. The $27 million decrease to other assets is related to prepaid commissions that do not meet the definition of an asset upon emergence as there is no future benefit to the Successor Company. 29. Deferred Revenue. The fair value of deferred revenue, which principally relates to payments on annual maintenance contracts, was determined by deducting selling costs and associated profit from the Predecessor Company deferred revenue balance to arrive at the costs and profit associated with fulfilling the liability. Additionally, the decrease includes the impact of an accounting policy change whereby the Successor Company no longer recognizes deferred revenue relating to sales transactions that have been billed, but for which the related account receivable has not yet been collected. 30. Other Current Liabilities. The decrease of $3 million to other current liabilities is related to the fair value of real estate leases determined to be above or below market using the income approach based on the difference between the contractual rental rate and the estimated market rental rate, discounted utilizing a risk-related discount rate. 31. Long-term Debt . The fair value of the Term Loan Credit Agreement was determined based on a market approach utilizing market-clearing data on the valuation date in addition to bid/ask prices. 32. Deferred Income Taxes. The adjustment represents the establishment of deferred tax liabilities related to book/tax differences created by fresh start accounting adjustments. The amount is net of the release of the valuation allowance on deferred tax assets, which management believes more likely than not will be realized as a result of future taxable income from the reversal of such deferred tax liabilities. 33. Business Restructuring Reserve. The Company recorded an increase to its non-current business restructuring reserves based on estimated future cash flows applied to a current discount rate at emergence. 34. Other Liabilities. A decrease in other liabilities of $43 million relates to deferred revenue and real estate leases as previously discussed. 35. Accumulated Other Comprehensive Loss. The remaining balance in Accumulated comprehensive loss was reversed to Reorganization expenses, net. 36. Fresh Start Adjustments. The following table reflects the cumulative impact of the fresh start adjustments as discussed above, the elimination of the Predecessor Company's accumulated other comprehensive loss and the adjustments required to eliminate accumulated deficit: (In millions) Eliminate Predecessor Intangible assets $ (298) Eliminate Predecessor Goodwill (3,541) Establish Successor Intangible assets 3,435 Establish Successor Goodwill 2,658 Fair value adjustment to Inventory 29 Fair value adjustment to Other current assets (66) Fair value adjustment to Property, plant and equipment 116 Fair value adjustment to Other assets (27) Fair value adjustment to Deferred revenue 235 Fair value adjustment to Business restructuring reserves (4) Fair value adjustment to Other current liabilities 3 Fair value adjustment to Long-term debt (96) Fair value adjustment to Other liabilities 43 Release Predecessor Accumulated comprehensive loss (790) Fresh start adjustments included in Reorganization items, net 1,697 Tax impact of fresh start adjustments (565) Gain on fresh start accounting, net $ 1,132

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	Disaggregation of Revenue The following tables provide the Company's disaggregated revenue for fiscal 2020 and 2019: Fiscal years ended September 30, (In millions) 2020 2019 Revenue: Products & Solutions $ 1,074 $ 1,228 Services 1,805 1,680 Unallocated Amounts (6) (21) $ 2,873 $ 2,887 Fiscal year ended September 30, 2020 (In millions) Products & Solutions Services Unallocated Total Revenue: U.S. $ 546 $ 1,097 $ (3) $ 1,640 International: Europe, Middle East and Africa 327 389 (2) 714 Asia Pacific 122 175 (1) 296 Americas International - Canada and Latin America 79 144 — 223 Total International 528 708 (3) 1,233 Total revenue $ 1,074 $ 1,805 $ (6) $ 2,873 Fiscal year ended September 30, 2019 (In millions) Products & Solutions Services Unallocated Total Revenue: U.S. $ 585 $ 981 $ (13) $ 1,553 International: Europe, Middle East and Africa 381 375 (3) 753 Asia Pacific 155 175 (3) 327 Americas International - Canada and Latin America 107 149 (2) 254 Total International 643 699 (8) 1,334 Total revenue $ 1,228 $ 1,680 $ (21) $ 2,887 Unallocated amounts represent the fair value adjustment to deferred revenue recognized upon emergence from bankruptcy and excluded from segment revenue.
Contract with Customer, Asset and Liability	The following table provides information about accounts receivable, contract assets and contract liabilities for the periods presented: As of September 30, (In millions) 2020 2019 Increase (Decrease) Accounts receivable, net $ 275 $ 314 $ (39) Contract assets: Current $ 296 $ 187 $ 109 Non-current (Other assets) 71 16 55 $ 367 $ 203 $ 164 Cost of obtaining a contract: Current (Contract costs) $ 92 $ 89 $ 3 Non-current (Other assets) 40 45 (5) $ 132 $ 134 $ (2) Cost to fulfill a contract: Current (Contract costs) $ 23 $ 25 $ (2) Contract liabilities: Current $ 446 $ 472 $ (26) Non-current 373 78 295 $ 819 $ 550 $ 269

Leases, Codification Topic 842

Leases, Codification Topic 842 (Tables)	12 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Lease, Cost	The following table details the components of net lease expense for fiscal 2020: (In millions) Fiscal year ended Operating lease cost (1) $ 67 Short-term lease cost (1) 5 Variable lease cost (1)(2) 17 Finance lease amortization of right-of-use assets (1) 4 Sublease income (3) (5) Total lease cost $ 88 (1) Allocated between Cost of products and services, and Operating expenses. (2) Includes real estate taxes and other charges for non-lease services payable to lessors and recognized in the period incurred. (3) Included in Other income, net.
Lessee, Finance Leases Table Text Block	The Company's right-of-use assets and lease liabilities for financing leases are included in the Consolidated Balance Sheet as follows: (In millions) September 30, 2020 ASSETS Property, plant and equipment, net $ 12 LIABILITIES Other current liabilities 8 Other liabilities 9
Finance and Operating Leases, Liabilities, Maturities Table Text Block	The following table presents the Company's annual maturity of lease payments, weighted average remaining lease term and weighted average interest rate for operating and financing leases as of September 30, 2020: (In millions) Operating Leases Financing Leases 2021 58 9 2022 49 4 2023 36 3 2024 25 2 2025 14 — 2026 and thereafter 22 — Total lease payments 204 18 Less: imputed interest (26) (1) Total lease liability $ 178 $ 17 Weighted average remaining lease term 4.5 years 2.7 years Weighted average interest rate 6.1 % 5.4 %
Schedule of Future Minimum Lease Payments for Capital Leases	The following table presents the Company's future minimum lease payments under non-cancelable leases as of September 30, 2019, which was prior to the adoption of ASC 842: In millions Operating Leases Capital Leases 2020 $ 51 $ 12 2021 39 6 2022 33 2 2023 22 — 2024 17 — 2025 and thereafter 29 — Total lease payments $ 191 20 Less: imputed interest (1) Total lease liability $ 19

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Sep. 30, 2020
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class	The Company's intangible assets consist of the following for the periods indicated: (In millions) Customer Trademarks Total Balance as of September 30, 2020 Finite-lived intangible assets: Cost $ 961 $ 2,153 $ 42 $ 3,156 Accumulated amortization (482) (433) (18) (933) Finite-lived intangible assets, net 479 1,720 24 2,223 Indefinite-lived intangible assets: Cost — — 333 333 Accumulated impairment — — — — Indefinite-lived intangible assets, net — — 333 $ 333 Intangible assets, net $ 479 $ 1,720 $ 357 $ 2,556 Balance as of September 30, 2019 Finite-lived intangible assets: Cost $ 960 $ 2,154 $ 42 $ 3,156 Accumulated amortization (308) (279) (11) (598) Finite-lived intangible assets, net 652 1,875 31 2,558 Indefinite-lived intangible assets: Cost $ 2 $ — $ 333 $ 335 Accumulated impairment (2) — — (2) Indefinite-lived intangible assets, net $ — $ — $ 333 $ 333 Intangible assets, net $ 652 $ 1,875 $ 364 $ 2,891
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Future amortization expense of intangible assets as of September 30, 2020 for the fiscal years ending September 30, is as follows: (In millions) 2021 $ 331 2022 304 2023 287 2024 185 2025 and thereafter 1,116 Total $ 2,223

Supplementary Financial Infor_2

Supplementary Financial Information (Tables)	12 Months Ended
	Sep. 30, 2020
Supplementary Financial Information [Abstract]
Consolidated Statements of Operations Information	The following table presents a summary of depreciation and amortization and Other income (expense), net for the periods indicated: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 DEPRECIATION AND AMORTIZATION Amortization of intangible assets (included in Costs and Operating expenses) $ 335 $ 336 $ 262 $ 13 Depreciation and amortization of property, plant and equipment and internal use software (included in Costs and Operating expenses) 88 107 122 18 Total depreciation and amortization $ 423 $ 443 $ 384 $ 31 OTHER INCOME (EXPENSE), NET Interest income $ 6 $ 14 $ 5 $ 2 Foreign currency (losses) gains, net (16) (8) 28 — Gain on investments in equity and debt securities, net 49 — — — Other pension and post-retirement benefit credits (costs), net 22 7 13 (8) Change in fair value of Emergence Date Warrants (3) 29 (17) — Sublease income 5 — — — Income from transition services agreement, net — — 5 3 Other, net — (1) 1 1 Total other income (expense), net $ 63 $ 41 $ 35 $ (2)
Summary of Reorganization Items	A summary of Reorganization items, net for the periods indicated is presented in the following table: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 REORGANIZATION ITEMS, NET Net gain on settlement of Liabilities subject to compromise $ — $ — $ — $ 1,778 Net gain on fresh start adjustments — — — 1,697 Bankruptcy-related professional fees — — — (56) Other items, net — — — (3) Reorganization items, net $ — $ — $ — $ 3,416 Cash payments for reorganization items $ — $ — $ 1 $ 2,524
Consolidated Balance Sheet Information	Consolidated Balance Sheet Information Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 VALUATION AND QUALIFYING ACCOUNTS Allowance for Doubtful Accounts Receivable: Balance at beginning of period $ 4 $ 2 $ — $ 13 Increase in expense 5 2 2 1 Reductions (2) — — (1) Impact of fresh start accounting — — — (13) Balance at end of period $ 7 $ 4 $ 2 $ — Deferred Tax Asset Valuation Allowance: Balance at beginning of period $ 928 $ 919 $ 836 $ 2,152 Increase (decrease) in expense 58 43 105 (452) Additions (reductions) 67 (34) (22) (393) Impact of fresh start accounting — — — (471) Balance at end of period $ 1,053 $ 928 $ 919 $ 836
Property, Plant and Equipment	As of September 30, (In millions) 2020 2019 PROPERTY, PLANT AND EQUIPMENT, NET Leasehold improvements $ 97 $ 101 Machinery and equipment 265 221 Assets under construction 30 30 Internal use software 188 154 Total property, plant and equipment 580 506 Less: Accumulated depreciation and amortization (312) (251) Property, plant and equipment, net $ 268 $ 255
Supplemental Cash Flow Information	Supplemental Cash Flow Information Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 OTHER PAYMENTS Interest payments $ 197 $ 206 $ 149 $ 15 Income tax payments 101 56 22 7 NON-CASH INVESTING ACTIVITIES Acquisition of equipment under finance leases $ 9 $ 3 $ 2 $ — (Decrease) increase in Accounts payable, Other current liabilities and Other liabilities for Capital expenditures (4) 6 1 — The following table presents a reconciliation of cash, cash equivalents, and restricted cash that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows for the periods presented: Successor Predecessor As of September 30, (In millions) 2020 2019 2018 December 15, 2017 CASH, CASH EQUIVALENTS, AND RESTRICTED CASH Cash and cash equivalents $ 727 $ 752 $ 700 $ 366 Restricted cash included in other current assets — — — 65 Restricted cash included in other assets 4 4 4 4 Total cash, cash equivalents, and restricted cash $ 731 $ 756 $ 704 $ 435

Business Restructuring Reserv_2

Business Restructuring Reserves and Programs (Tables)	12 Months Ended
	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Schedule of Restructuring and Related Costs	The following table summarizes the restructuring charges by activity for the periods presented: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 Employee separation costs $ 6 $ 19 $ 70 $ 13 Facility exit costs 24 3 11 $ 1 Total restructuring charges $ 30 $ 22 $ 81 $ 14 The following table summarizes the activity for employee separation costs recognized under the Company's restructuring programs for the periods presented: (In millions) Fiscal 2020 Restructuring Program (2) Fiscal 2019 Restructuring Program (3) Fiscal 2018 Restructuring Program (3) Fiscal 2008 through 2017 Restructuring Programs (3) Total Accrual balance as of September 30, 2017 (Predecessor) $ — $ — $ — $ 55 $ 55 Cash payments — — (3) (4) (7) Restructuring charges — — 12 1 13 Adjustments (1) — — — 4 4 Impact of foreign currency fluctuations — — — — — Accrual balance as of December 15, 2017 (Predecessor) $ — $ — $ 9 $ 56 $ 65 Accrual balance as of December 16, 2017 (Successor) $ — $ — $ 9 $ 56 $ 65 Cash payments — — (23) (17) (40) Restructuring charges — — 70 — 70 Adjustments (1) — — — — — Impact of foreign currency fluctuations — — (2) (1) (3) Accrual balance as of September 30, 2018 (Successor) — — 54 38 92 Cash payments — (8) (19) (16) (43) Restructuring charges — 20 — — 20 Adjustments (1) — — (2) 1 (1) Impact of foreign currency fluctuations — (1) (2) (1) (4) Accrual balance as of September 30, 2019 (Successor) — 11 31 22 64 Cash payments (1) (5) (11) (9) (26) Restructuring charges 8 — — — 8 Adjustments (1) — — (1) (1) (2) Impact of foreign currency fluctuations 1 1 2 1 5 Accrual balance as of September 30, 2020 (Successor) $ 8 $ 7 $ 21 $ 13 $ 49 (1) Includes changes in estimates for increases and decreases in costs related to the Company's restructuring programs, which are recorded in Restructuring charges, net in the Consolidated Statements of Operations in the period of the adjustment. (2) Payments related to the fiscal 2020 restructuring program are expected to be completed in fiscal 2027. (3) Payments related to the fiscal 2019, 2018 and 2008 through 2017 restructuring programs are expected to be completed in fiscal 2026.

Financing Arrangements - (Table

Financing Arrangements - (Tables)	12 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	The following table reflects principal amounts of debt and debt net of discounts and issuance costs for the periods presented: September 30, 2020 September 30, 2019 (In millions) Principal amount Net of discounts and issuance costs Principal amount Net of discounts and issuance costs Term Loan Credit Agreement due December 15, 2024 and 2027 $ 1,643 $ 1,611 $ 2,874 $ 2,846 Senior 6.125% Notes due September 15, 2028 1,000 984 — — Convertible 2.25% Senior Notes due June 15, 2023 350 291 350 273 Total debt $ 2,993 2,886 $ 3,224 3,119 Debt maturing within one year — (29) Long-term debt, net of current portion $ 2,886 $ 3,090
Schedule of Maturities of Long-term Debt	The stated annual maturity of total debt for the fiscal years ended September 30, consist of: (In millions) 2021 $ — 2022 — 2023 350 2024 — 2025 and thereafter 2,643 Total $ 2,993
Convertible Debt	The net carrying amount of the Convertible Notes for the periods indicated was as follows: As of September 30, (In millions) 2020 2019 Principal $ 350 $ 350 Less: Unamortized debt discount (55) (72) Unamortized issuance costs (4) (5) Net carrying amount $ 291 $ 273

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Assumptions Used	The fair value of the Emergence Date Warrants as of September 30, 2020 and 2019 was determined using the input assumptions summarized below: As of September 30, 2020 2019 Expected volatility 68.53 % 56.89 % Risk-free interest rates 0.14 % 1.55 % Contractual remaining life (in years) 2.21 3.21 Price per share of common stock $15.20 $10.23
Schedule of Derivative Instruments in Balance Sheet	The following table summarizes the fair value of the Company's derivatives on a gross basis, including accrued interest, segregated between those that are designated as hedging instruments and those that are not designated as hedging instruments: September 30, 2020 September 30, 2019 (In millions) Balance Sheet Caption Asset Liability Asset Liability Derivatives Designated as Hedging Instruments: Interest rate contracts Other current liabilities — 43 — 23 Interest rate contracts Other liabilities — 58 — 58 — 101 — 81 Derivatives Not Designated as Hedging Instruments: Interest rate contracts Other current liabilities — 7 — — Interest rate contracts Other liabilities — 9 — — Foreign exchange contracts Other current assets 1 — 1 — Foreign exchange contracts Other current liabilities — 2 — — Emergence Date Warrants Other liabilities — 8 — 5 1 26 1 5 Total derivative fair value $ 1 $ 127 $ 1 $ 86
Derivatives Designated as Cash Flow Hedges	The following table provides information regarding the location and amount of pre-tax (losses) gains for interest rate swaps designated as cash flow hedges: Fiscal years ended September 30, Period from December 16, 2017 2020 2019 (In millions) Interest Expense Other Comprehensive (Loss) Income Interest Expense Other Comprehensive (Loss) Income Interest Expense Other Comprehensive (Loss) Income Financial Statement Line Item in which Cash Flow Hedges are Recorded $ (226) $ (72) $ (237) $ (191) $ (169) $ 18 Impact of cash flow hedging relationships: Loss recognized in AOCI - on interest rate swaps — (69) — (87) — (9) Interest expense reclassified from AOCI (35) 35 (10) 10 (6) 6
Derivatives Not Designated As Hedging Instruments	The following table provides information regarding the pre-tax (losses) gains for derivatives not designated as hedging instruments on the Consolidated Statements of Operations: Fiscal years ended September 30, Period from December 16, 2017 (In millions) Location of Derivative Pre-tax Gain (Loss) 2020 2019 Emergence Date Warrants Other income (expense), net (3) $ 29 $ (17) Foreign exchange contracts Other income (expense), net (1) (5) —
Schedule of Outstanding Derivative Positions Presented on a Net Basis	The following table provides information on the Company's derivative positions as if those subject to master netting arrangements were presented on a net basis, allowing for the right to offset by counterparty per the master netting agreements: September 30, 2020 September 30, 2019 (In millions) Asset Liability Asset Liability Gross amounts recognized in the Consolidated Balance Sheet $ 1 $ 127 $ 1 $ 86 Gross amount subject to offset in master netting arrangements not offset in the Consolidated Balance Sheet (1) (1) (1) (1) Net amounts $ — $ 126 $ — $ 85

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring	Assets and liabilities measured at fair value on a recurring basis as of September 30, 2020 and 2019 were as follows: September 30, 2020 September 30, 2019 Fair Value Measurements Using Fair Value Measurements Using (In millions) Total Level 2 Level 3 Total Level 2 Level 3 Assets: Investments in debt securities $ — $ — $ — $ — $ 10 $ — $ — $ 10 Foreign exchange contracts 1 — 1 — 1 — 1 — Total assets $ 1 $ — $ 1 $ — $ 11 $ — $ 1 $ 10 Liabilities: Interest rate contracts $ 117 $ — $ 117 $ — $ 81 $ — $ 81 $ — Spoken acquisition Earn-outs — — — — 5 — — 5 Foreign exchange contracts 2 — 2 — — — — — Emergence Date Warrants 8 — — 8 5 — — 5 Total liabilities $ 127 $ — $ 119 $ 8 $ 91 $ — $ 81 $ 10
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table summarizes the activity for the Company's Level 3 assets and liabilities measured at fair value on a recurring basis: (In millions) Emergence Date Warrants Spoken acquisition earn-outs Investments in debt securities Balance as of September 30, 2019 $ 5 $ 5 $ 10 Impairment (1) — — (10) Changes in fair value (2) 3 — — Settlement — (5) — Balance as of September 30, 2020 $ 8 $ — $ — (1) During fiscal 2020, the Company recorded an other-than-temporary impairment charge for a $10 million credit loss on its investments in debt securities. See Note 6, "Business Combinations and Strategic Partnerships and Investments," for additional information. (2) Changes in fair value of the Emergence Date Warrants are included in Other income (expense), net.
Fair Value, by Balance Sheet Grouping	The estimated fair values of the Company’s Term Loan Credit Agreement, Senior Notes and Convertible Notes at September 30, 2020 and 2019 were as follows: September 30, 2020 September 30, 2019 (In millions) Principal amount Fair value Principal amount Fair value Term Loan Credit Agreement due December 15, 2024 and 2027 $ 1,643 $ 1,624 $ 2,874 $ 2,739 Senior 6.125% Notes due September 15, 2028 1,000 1,022 — — Convertible 2.25% Senior Notes due June 15, 2023 350 331 350 298 Total $ 2,993 $ 2,977 $ 3,224 $ 3,037

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The following table presents the U.S. and foreign components of (loss) income before income taxes and the (provision for) benefit from income taxes for the periods indicated: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 (LOSS) INCOME BEFORE INCOME TAXES: U.S. $ (639) $ (510) $ (165) $ 3,353 Foreign 21 (159) (94) 83 (Loss) income before income taxes $ (618) $ (669) $ (259) $ 3,436 (PROVISION FOR) BENEFIT FROM INCOME TAXES: CURRENT Federal $ (58) $ (20) $ — $ — State and local (10) (7) 4 — Foreign (23) (29) (40) (4) (91) (56) (36) (4) DEFERRED Federal 30 47 530 (453) State and local 3 10 34 (19) Foreign (4) (3) 18 17 29 54 582 (455) (Provision for) benefit from income taxes $ (62) $ (2) $ 546 $ (459)
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company's deferred tax assets and liabilities as of the periods indicated were as follows: As of September 30, (In millions) 2020 2019 DEFERRED INCOME TAX ASSETS: Benefit obligations $ 218 $ 225 Net operating losses/credit carryforwards 981 918 Property, plant and equipment 8 15 Other/accrued liabilities 13 — Valuation allowance (1,053) (928) Gross deferred income tax assets 167 230 DEFERRED INCOME TAX LIABILITIES: Goodwill and intangible assets (174) (213) Other/accrued liabilities — (54) Gross deferred income tax liabilities (174) (267) Net deferred income tax liabilities $ (7) $ (37)
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the Company’s (loss) income before income taxes at the U.S. federal statutory rate to the (provision for) benefit from income taxes is as follows: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 Income tax benefit (provision) computed at the U.S. Federal statutory rate $ 130 $ 140 $ 64 $ (1,203) State and local income taxes, net of federal income tax effect 2 11 (12) 10 Tax differentials on foreign earnings — (11) (12) 182 Loss on foreign subsidiaries 28 29 43 — Taxes on unremitted foreign earnings and profits (8) (4) 4 7 Non-deductible portion of goodwill (125) (123) — — Non-deductible reorganization items — — — (11) Adjustment to deferred taxes (14) 16 4 (1) Audit settlements and accruals 6 5 (48) (6) Credits and other taxes (2) 4 (5) (1) Impact of Tax Cuts and Jobs Act (3) 1 245 — NOL recognition / intellectual property — — 366 — Warrants (1) 6 (4) — Debt refinancing — — (8) — Non-deductible impact of fresh start accounting — — — (555) Non-taxable cancellation of debt income — — — 313 Attribute reduction — — — (452) Rate changes (3) (19) (3) — U.S. tax on foreign source income — — (10) (2) Valuation allowance (58) (43) (85) 1,199 Other differences—net (14) (14) 7 61 (Provision for) benefit from income taxes $ (62) $ (2) $ 546 $ (459)
Schedule of Unrecognized Tax Benefits Roll Forward	(In millions) Gross UTB balance at September 30, 2017 (Predecessor) 268 Additions based on tax positions relating to the period 4 Gross UTB balance at December 15, 2017 (Predecessor) $ 272 Gross UTB balance at December 16, 2017 (Successor) $ 272 Additions based on tax positions relating to the period 57 Changes based on tax positions relating to prior periods (143) Statute of limitations expirations (12) Gross UTB balance at September 30, 2018 (Successor) 174 Additions based on tax positions relating to the period 10 Changes based on tax positions relating to prior periods (32) Statute of limitations expirations (5) Gross UTB balance at September 30, 2019 (Successor) $ 147 Additions based on tax positions relating to the period 4 Changes based on tax positions relating to prior periods (1) Settlements (2) Statute of limitations expirations (8) Gross UTB Balance at September 30, 2020 (Successor) $ 140

Benefit Obligations (Tables)

Benefit Obligations (Tables)	12 Months Ended
	Sep. 30, 2020
Retirement Benefits [Abstract]
Schedule of Defined Benefit Plans Disclosures	A reconciliation of the changes in the benefit obligations and fair value of assets of the defined benefit pension and post-retirement plans, the funded status of the plans and the amounts recognized in the Consolidated Balance Sheets are provided in the tables below: Fiscal years ended September 30, (In millions) 2020 2019 Pension Benefits - U.S. Change in benefit obligation Projected benefit obligation at beginning of period $ 1,134 $ 1,050 Service cost 4 3 Interest cost 29 40 Actuarial loss 55 131 Benefits paid (77) (90) Projected benefit obligation at end of period $ 1,145 $ 1,134 Change in plan assets Fair value of plan assets at beginning of period $ 915 $ 881 Actual return on plan assets 79 97 Employer contributions 10 27 Benefits paid (77) (90) Fair value of plan assets at end of period $ 927 $ 915 Underfunded status at end of period $ (218) $ (219) Amount recognized in the Consolidated Balance Sheets consists of: Accrued benefit liability, noncurrent $ (218) $ (219) Net amount recognized $ (218) $ (219) Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of: Net actuarial loss 110 79 Net amount recognized $ 110 $ 79 Weighted average assumptions used to determine benefit obligations Discount rate 2.50 % 3.09 % Rate of compensation increase 3.00 % 3.00 % Fiscal years ended September 30, (In millions) 2020 2019 Pension Benefits - Non-U.S. Change in benefit obligation Projected benefit obligation at beginning of period $ 573 $ 536 Service cost 7 6 Interest cost 5 10 Actuarial (gain) loss (34) 76 Benefits paid (21) (22) Foreign currency exchange rate changes 42 (32) Curtailments, settlements and other 1 (1) Projected benefit obligation at end of period $ 573 $ 573 Change in plan assets Fair value of plan assets at beginning of period $ 15 $ 15 Actual return on plan assets — 1 Employer contributions 22 23 Benefits paid (21) (22) Foreign currency exchange rate changes 2 (1) Settlements — (1) Fair value of plan assets at end of period $ 18 $ 15 Underfunded status at end of period $ (555) $ (558) Amount recognized in the Consolidated Balance Sheets consists of: Noncurrent assets $ 1 $ 1 Accrued benefit liability, current (25) (19) Accrued benefit liability, noncurrent (531) (540) Net amount recognized $ (555) $ (558) Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of: Net actuarial loss $ 22 $ 55 Net amount recognized $ 22 $ 55 Weighted average assumptions used to determine benefit obligations Discount rate 0.86 % 0.87 % Rate of compensation increase 2.60 % 2.59 % Fiscal years ended September 30, (In millions) 2020 2019 Post-retirement Benefits - U.S. Change in benefit obligation Benefit obligation at beginning of period $ 404 $ 368 Service cost 1 1 Interest cost 11 14 Actuarial loss 30 44 Benefits paid (15) (16) Plan amendments — (7) Projected benefit obligation at end of period $ 431 $ 404 Change in plan assets Fair value of plan assets at beginning of period $ 191 $ 178 Actual return on plan assets 20 17 Employer contributions 10 12 Benefits paid (15) (16) Fair value of plan assets at end of period $ 206 $ 191 Underfunded status at end of period $ (225) $ (213) Amount recognized in the Consolidated Balance Sheets consists of: Accrued benefit liability, current $ (10) $ (13) Accrued benefit liability, noncurrent (215) (200) Net amount recognized $ (225) $ (213) Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of: Net prior service credit $ (6) $ (7) Net actuarial loss $ 23 $ 3 Net amount recognized $ 17 $ (4) Weighted average assumptions used to determine benefit obligations Discount rate 2.69 % 3.17 % Rate of compensation increase 3.00 % 3.00 %
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	The following table provides the accumulated benefit obligation for all defined benefit pension plans and information for pension plans with an accumulated benefit obligation in excess of plan assets: Pension Benefits - U.S. Pension Benefits - Non-U.S. (In millions) September 30, 2020 September 30, 2019 September 30, 2020 September 30, 2019 Accumulated benefit obligation for all plans $ 1,145 $ 1,134 $ 555 $ 555 Plans with accumulated benefit obligation in excess of plan assets Projected benefit obligation $ 1,145 $ 1,134 $ 567 $ 568 Accumulated benefit obligation $ 1,145 $ 1,134 $ 549 $ 550 Fair value of plan assets $ 927 $ 915 $ 12 $ 9
Schedule of Expected Benefit Payments	Estimated future benefits expected to be paid in each of the next five fiscal years, and in aggregate for the five fiscal years thereafter, are presented below: Pension Benefits Post-retirement (In millions) U.S. Non-U.S. 2021 $ 74 $ 24 $ 17 2022 73 24 18 2023 73 23 19 2024 72 23 19 2025 71 24 20 2026 - 2030 338 136 107 Total $ 701 $ 254 $ 200
Schedule of Net Benefit Costs	The components of the pension and post-retirement net periodic benefit (credit) cost for the periods indicated are provided in the table below: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 Pension Benefits - U.S. Components of net periodic benefit (credit) cost Service cost $ 4 $ 3 $ 3 $ 1 Interest cost 29 40 28 22 Expected return on plan assets (55) (60) (51) (38) Amortization of actuarial loss — — — 20 Net periodic benefit (credit) cost $ (22) $ (17) $ (20) $ 5 Weighted average assumptions used to determine net periodic benefit cost Discount rate 2.84 % 3.94 % 3.29 % 3.19 % Expected return on plan assets 6.40 % 7.00 % 7.65 % 7.75 % Rate of compensation increase 3.00 % 4.00 % 4.00 % 4.00 % Pension Benefits - Non-U.S. Components of net periodic benefit cost Service cost $ 7 $ 6 $ 5 $ 2 Interest cost 5 10 7 3 Expected return on plan assets (1) (1) — (1) Amortization of actuarial loss — — — 2 Net periodic benefit cost $ 11 $ 15 $ 12 $ 6 Weighted average assumptions used to determine net periodic benefit cost Discount rate 0.87 % 1.92 % 1.92 % 1.22 % Expected return on plan assets 3.72 % 3.67 % 3.68 % 1.82 % Rate of compensation increase 2.59 % 2.58 % 3.62 % 3.45 % Post-retirement Benefits - U.S. Components of net periodic benefit cost Service cost $ 1 $ 1 $ 1 $ — Interest cost 11 14 11 3 Expected return on plan assets (10) (9) (8) (2) Amortization of prior service credit (1) — — (3) Amortization of actuarial (gain) loss — (1) — 2 Net periodic benefit cost $ 1 $ 5 $ 4 $ — Weighted average assumptions used to determine net periodic benefit cost Discount rate 2.18 % 4.02 % 3.39 % 3.37 % Expected return on plan assets 5.50 % 5.50 % 5.50 % 5.90 % Rate of compensation increase 3.00 % 4.00 % 4.00 % 4.00 %
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)	Other changes in plan assets and benefit obligations recognized in other comprehensive (loss) income are provided in the tables below: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 Pension Benefits - U.S. Net loss (gain) $ 31 $ 94 $ (15) $ — Amortization of actuarial loss — — — (20) Reorganization adjustments — — — (1,147) Total recognized in Other comprehensive (loss) income $ 31 $ 94 $ (15) $ (1,167) Total recognized in net periodic benefit cost and Other comprehensive (loss) income (1) $ 9 $ 77 $ (35) $ (722) Pension Benefits - Non-U.S. Net (gain) loss $ (33) $ 76 $ (19) $ 22 Foreign exchange rate loss — (2) — — Amortization of actuarial loss — — — (2) Reorganization adjustments — — — (163) Total recognized in Other comprehensive (loss) income $ (33) $ 74 $ (19) $ (143) Total recognized in net periodic benefit cost and Other comprehensive (loss) income (1) $ (22) $ 89 $ (7) $ (137) Post-retirement Benefits - U.S. Net loss (gain) $ 20 $ 36 $ (34) $ — Prior service credit — (7) — — Amortization of prior service credit 1 — — 3 Amortization of actuarial gain (loss) — 1 — (2) Reorganization adjustments — — — (40) Total recognized in Other comprehensive (loss) income $ 21 $ 30 $ (34) $ (39) Total recognized in net periodic benefit cost and Other comprehensive (loss) income (1) $ 22 $ 35 $ (30) $ 2 (1)
Schedule of Allocation of Plan Assets	The weighted average asset allocation of the pension and post-retirement plans by asset category and target allocation is as follows: As of September 30, Asset Category 2020 2019 Long-term Target Pension Benefits - U.S. Debt Securities 52 % 52 % 52 % Equity Securities 29 % 29 % 34 % Hedge Funds 6 % 7 % 6 % Real Estate 5 % 6 % 6 % Commodities 2 % 2 % 2 % Other (1) 6 % 4 % — % Total 100 % 100 % 100 % Pension Benefits - Non-U.S. Debt Securities 22 % 27 % Asset Allocation Fund 11 % 13 % Insurance Contracts 67 % 60 % Total 100 % 100 % Post-retirement Benefits - U.S. Equity Securities 34 % 40 % 35 % Debt Securities 66 % 60 % 65 % Total 100 % 100 % 100 % (1) Other includes cash/cash equivalents, derivative financial instruments and payables/receivables for pending transactions. The following table summarizes the fair value measurements of the U.S. pension plan assets by asset class: As of September 30, 2020 As of September 30, 2019 (In millions) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total U.S. Government debt securities (a) $ — $ 132 $ — $ 132 $ — $ 125 $ — $ 125 Derivative instruments (b) — — — — (2) — — (2) Total assets in the fair value hierarchy — 132 — 132 (2) 125 — 123 Investments measured at net asset value: (c) Real estate (d) 50 55 Private equity (e) 2 4 Multi-strategy hedge funds (f) 56 65 Investment funds: (g) Cash equivalents 46 37 Long duration fixed income 327 328 High-yield debt 19 19 U.S. equity 154 144 Non-U.S. equity 83 92 Emerging market equity 33 29 Commodities 20 14 Total investments measured at net asset value 790 787 Other plan assets, net 5 5 Total plan assets at fair value $ — $ 132 $ — $ 927 $ (2) $ 125 $ — $ 915 (a) Includes U.S. Treasury STRIPS, which are generally valued using institutional bid evaluations from various contracted pricing vendors. Institutional bid evaluations are estimated prices that represent the price a dealer would pay for a security. Pricing inputs to the institutional bid evaluation vary by security and include benchmark yields, reported trades, unadjusted broker/dealer quotes, issuer spreads, bids, offers or other observable market data. (b) Includes future contracts that are generally valued using the last trade price at which a specific contract/security was last traded on the primary exchange, which is provided by a contracted vendor. If pricing is not available from the contracted vendor, then pricing is obtained from other sources such as Bloomberg, broker bid, ask/offer quotes or the investment manager. (c) These investments are measured at fair value using the net asset value per share or its equivalent ("NAV") and have therefore not been classified in the fair value hierarchy. (d) Includes open ended real estate commingled funds, close ended real estate limited partnerships, and insurance company separate accounts that invest primarily in U.S. office, lodging, retail and residential real estate. The insurance company separate accounts and the commingled funds account for their portfolio of assets at fair value and calculate the NAV on either a monthly or quarterly basis. Shares can be redeemed at the NAV on a quarterly basis, provided a written redemption request is received in advance (generally 45-91 days) of the redemption date. Therefore, the undiscounted NAV is used as the fair value measurement. For limited partnerships, the fair value of the underlying assets and the capital account for each investor is determined by the General Partner ("GP"). The valuation techniques used by the GP generally consist of unobservable inputs such as discounted cash flow analysis, analysis of recent comparable sales transactions, actual sale negotiations and bona fide purchase offers received from third parties. The partnerships are typically funded over time as capital is needed to fund asset purchases, and distributions from the partnerships are received as the partnerships liquidate their underlying asset holdings. Therefore, the life cycle for a typical investment in a real estate limited partnership is expected to be approximately 10 years from initial funding. (e) Includes limited partner interests in various limited partnerships ("LPs") that invest primarily in U.S. and non-U.S. investments either directly, or through other partnerships or funds with a focus on venture capital, buyouts, expansion capital, or companies undergoing financial distress or significant restructuring. The NAV of the LPs and of the capital account of each investor is determined by the GP of each LP. Marketable securities held by the LPs are valued based on the closing price on the valuation date on the exchange where they are principally traded and may be adjusted for legal restrictions, if any. Investments without a public market are valued based on assumptions made and valuation techniques used by the GP, which consist of unobservable inputs. Such valuation techniques may include discounted cash flow analysis, analysis of recent comparable sales transactions, actual sale negotiations and bona fide purchase offers received from third parties. The LPs are typically funded over time as capital is needed to fund purchases and distributions are received as the partnerships liquidate their underlying asset holdings. (f) Includes hedge funds and funds of funds that pursue multiple strategies to diversify risks and reduce volatility. The funds account for their portfolio of assets at fair value and calculate the NAV of their fund on a monthly basis. The funds limit the frequency of redemptions to manage liquidity and protect the interests of the funds and its shareholders. (g) Includes open-end funds and unit investment trusts that invest in various asset classes including: U.S. and non-U.S. corporate debt, U.S. government debt, municipal bonds, U.S. equity, non-U.S. developed and emerging markets equity, and commodities. The funds account for their portfolio of assets at fair value and calculate the NAV of the funds on a daily basis, and shares can be redeemed at the NAV. Therefore, the undiscounted NAV as reported by the funds is used as the fair value measurement. The following table summarizes the fair value of the non-U.S. pension plan assets by asset class: As of September 30, (In millions) 2020 2019 Investments measured at net asset value: (a) Investment funds: (b) Debt securities $ 4 $ 4 Asset allocation 2 2 Insurance contracts (c) 12 9 Total plan assets at fair value $ 18 $ 15 (a) These investments are measured at fair value using the NAV and have therefore not been classified in the fair value hierarchy. (b) Includes collective investment funds that invest in various asset classes including U.S. and non-U.S. corporate debt and equity, and derivatives. The funds account for their portfolio of assets at fair value and calculate the NAV of the funds on a daily basis, and shares can be redeemed at the NAV. Therefore, the undiscounted NAV as reported by the funds is used as the fair value measurement. (c) Most non-U.S. pension plans are funded through insurance contracts, which provide for a guaranteed interest credit and a profit-sharing adjustment based on the actual performance of the underlying investment assets of the insurer. The fair value of the contract is determined by the insurer based on the premiums paid by the Company plus interest credits plus the profit-sharing adjustment less benefit payments. The underlying assets of the insurer are invested in compliance with local rules or law, which tend to require a high allocation to fixed income securities. The following table summarizes the fair value of the post-retirement plan assets by asset class: As of September 30, (In millions) 2020 2019 Investments measured at net asset value: (a) Group life insurance contract measured at net asset value (b) $ 206 $ 191 Total plan assets at fair value $ 206 $ 191 (a) These investments are measured at fair value using the NAV and have therefore not been classified in the fair value hierarchy.

Share-based Compensation (Table

Share-based Compensation (Tables)	12 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
The weighted average grant date assumptions used in calculating the fair value of options granted	The grant date fair value was determined using a Black-Scholes option pricing model with the following average grant date assumptions: Fiscal year ended Expected volatility (1) 93.51 % Risk-free interest rate (2) 0.13 % Dividend yield (3) — % (1) Expected volatility based on the Company's historical data. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the length of the offering period. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends.
A summary of option activity	A summary of option activity for fiscal 2020 is presented below: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding at September 30, 2019 925 $ 19.59 Granted 164 11.38 Forfeited or expired (147) 19.84 Outstanding at September 30, 2020 942 $ 18.13 7.3 $ 625 Exercisable at September 30, 2020 715 $ 19.54 6.9 $ —
A summary of RSU activity	A summary of RSU activity for fiscal 2020 is presented below: Restricted Stock Units Weighted Average Grant-Date Fair Value Non-vested at September 30, 2019 2,797 $ 15.60 Granted 2,128 12.42 Vested (1,533) 15.31 Forfeited (698) 15.30 Non-vested at September 30, 2020 2,694 $ 13.32
Share-based Compensation by Share-based Payment Award, Fair Value Assumptions	The grant date fair value of the Performance PRSUs was determined using a Monte Carlo simulation model that incorporated multiple valuation assumptions, including the probability of achieving the total shareholder return market condition and the following assumptions presented on a weighted-average basis: Fiscal years ended September 30, 2020 2019 Expected volatility (1) 55.75 % 53.00 % Risk-free interest rate (2) 1.61 % 2.46 % Dividend yield (3) — % — % (1) Expected volatility based on a blend of Company and peer group company historical data adjusted for the Company's leverage. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the remaining Performance Period as of the grant date. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends. Fiscal year ended Expected volatility (1) 53.76 % Risk-free interest rate (2) 2.45 % Dividend yield (3) — % (1) Expected volatility based on a blend of Company and peer group company historical data adjusted for the Company's leverage. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the remaining Performance Period as of the grant date. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends. Fiscal year ended Period from December 16, 2017 Emergence Date Exercise price $ 11.38 $ 21.66 $ 19.46 Expected volatility (1) 56.76 % 49.67 % 56.59 % Expected life (in years) (2) 5.97 5.86 6.65 Risk-free interest rate (3) 1.71 % 2.72 % 2.35 % Dividend yield (4) — % — % — % (1) Expected volatility based on peer group companies adjusted for the Company's leverage. (2) Expected life based on the vesting terms of the option and a contractual life of ten years. (3) Risk-free interest rate based on U.S. Treasury yields with a term equal to the expected option term. (4) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends.
Schedule of Nonvested Performance-based Units Activity	A summary of total PRSU activity for fiscal 2020 is presented below: Performance Restricted Stock Units Weighted Average Grant-Date Fair Value Non-vested at September 30, 2019 274 $ 11.18 Granted 662 13.69 Change in shares due to performance (314) 13.71 Forfeited (34) 13.29 Non-vested at September 30, 2020 588 $ 12.53

Net Income (Loss) Per Common _2

Net Income (Loss) Per Common Share (Tables)	12 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Schedule of Earnings (Loss) Per Share	The following table sets forth the calculation of net (loss) income attributable to common shareholders and the computation of basic and diluted (loss) earnings per share for the periods indicated: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions, except per share amounts) 2020 2019 (Loss) Earnings per share: Numerator Net (loss) income $ (680) $ (671) $ 287 $ 2,977 Dividends and accretion to preferred stockholders (7) — — (6) Undistributed (loss) income (687) (671) 287 2,971 Percentage allocated to common stockholders (1) 100.0 % 100.0 % 100.0 % 86.9 % Numerator for basic and diluted (loss) earnings per common share $ (687) $ (671) $ 287 $ 2,582 Denominator Denominator for basic (loss) earnings per weighted average common shares 92.2 110.8 109.9 497.3 Effect of dilutive securities Restricted stock units — — 1.2 — Denominator for diluted (loss) earnings per weighted average common shares 92.2 110.8 111.1 497.3 (Loss) earnings per common share Basic $ (7.45) $ (6.06) $ 2.61 $ 5.19 Diluted $ (7.45) $ (6.06) $ 2.58 $ 5.19 (1) Basic weighted average common stock outstanding 92.2 110.8 109.9 497.3 Basic weighted average common stock and common stock equivalents (preferred shares) 92.2 110.8 109.9 572.4 Percentage allocated to common stockholders 100.0 % 100.0 % 100.0 % 86.9 %

Operating Segments (Tables)

Operating Segments (Tables)	12 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Summarized Financial Information of Operating Segments	Summarized financial information relating to the Company's operating segments is shown in the following table for the periods indicated: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 REVENUE Products & Solutions $ 1,074 $ 1,228 $ 1,052 $ 253 Services 1,805 1,680 1,401 351 Unallocated Amounts (1) (6) (21) (206) — $ 2,873 $ 2,887 $ 2,247 $ 604 GROSS PROFIT Products & Solutions $ 669 $ 791 $ 696 $ 169 Services 1,092 996 843 196 Unallocated Amounts (2) (181) (212) (396) (3) 1,580 1,575 1,143 362 OPERATING EXPENSES Selling, general and administrative 1,013 1,001 888 264 Research and development 207 204 172 38 Amortization of intangible assets 161 162 127 10 Impairment charges 624 659 — — Restructuring charges, net 30 22 81 14 2,035 2,048 1,268 326 OPERATING (LOSS) INCOME (455) (473) (125) 36 INTEREST EXPENSE, OTHER INCOME (EXPENSE), NET AND REORGANIZATION ITEMS, NET (163) (196) (134) 3,400 (LOSS) INCOME BEFORE INCOME TAXES $ (618) $ (669) $ (259) $ 3,436 (1) Unallocated amounts in Revenue represent the fair value adjustment to deferred revenue recognized upon emergence from bankruptcy and excluded from segment revenue. (2) Unallocated amounts in Gross Profit include the fair value adjustments recognized upon emergence from bankruptcy and excluded from segment gross profit; the effect of the amortization of technology intangibles; and costs that are not core to the measurement of segment management’s performance, but rather are controlled at the corporate level. As of September 30, (In millions) 2020 2019 ASSETS: Products & Solutions $ 31 $ 662 Services 1,501 1,504 Unallocated Assets (1) 4,699 4,784 Total $ 6,231 $ 6,950 (1) Unallocated Assets consist of cash and cash equivalents, accounts receivable, contract assets, contract costs, deferred income tax assets, property, plant and equipment, operating lease right-of-use assets, acquired intangible assets and other assets. Unallocated Assets are managed at the corporate level and are not identified with a specific segment. The decrease in Products & Solutions total assets was mainly driven by the $624 million impairment of goodwill recorded during fiscal 2020 as described in Note 7, "Goodwill, net."
Revenue and Long-Lived Assets by Geographic Area	Financial information relating to the Company’s revenue and long-lived assets by geographic area is as follows: Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from (In millions) 2020 2019 REVENUE (1) : U.S. $ 1,640 $ 1,553 $ 1,184 $ 331 International: EMEA 714 753 603 166 APAC—Asia Pacific 296 327 256 57 Americas International—Canada and Latin America 223 254 204 50 Total International 1,233 1,334 1,063 273 Total $ 2,873 $ 2,887 $ 2,247 $ 604 As of September 30, (In millions) 2020 2019 LONG-LIVED ASSETS (2) U.S. $ 191 $ 184 International: EMEA 57 54 APAC—Asia Pacific 13 10 Americas International—Canada and Latin America 7 7 Total International 77 71 Total $ 268 $ 255 (1) Revenue is attributed to geographic areas based on the location of customers. (2) Represents property, plant and equipment, net.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive (Loss) Income (Tables)	12 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The components of Accumulated other comprehensive (loss) income for the periods indicated were as follows: (In millions) Change in Unamortized Pension, Post-retirement and Postemployment Benefit-related Items Foreign Currency Translation Unrealized Loss on Interest Rate Swaps Other Accumulated Other Comprehensive (Loss) Income Balance as of September 30, 2017 (Predecessor) (1,375) (72) — (1) (1,448) Other comprehensive (loss) income before reclassifications (24) 3 — — (21) Amounts reclassified to earnings 16 — — — 16 Pension settlement 721 — — — 721 Provision for income taxes (58) — — — (58) Balance as of December 15, 2017 (Predecessor) (720) (69) — (1) (790) Elimination of Predecessor Company Accumulated other comprehensive loss 720 69 — 1 790 Balance as of December 15, 2017 (Predecessor) $ — $ — $ — $ — $ — Balance as of December 16, 2017 (Successor) $ — $ — $ — $ — $ — Other comprehensive income (loss) before reclassifications 70 (31) (3) — 36 (Provision for) benefit from income taxes (19) — 1 — (18) Balance as of September 30, 2018 (Successor) 51 (31) (2) — 18 Other comprehensive (loss) income before reclassifications (186) 24 (87) — (249) Amounts reclassified to earnings — — 10 — 10 Benefit from income taxes 29 — 19 48 Balance as of September 30, 2019 (Successor) $ (106) $ (7) $ (60) $ — $ (173) Other comprehensive loss before reclassifications (2) (66) (69) — (137) Amounts reclassified to earnings — 27 35 — 62 Benefit from income taxes — — 3 — 3 Balance as of September 30, 2020 (Successor) $ (108) $ (46) $ (91) $ — $ (245)

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Sep. 30, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following tables present unaudited quarterly financial data. This information has been derived from the Company’s unaudited financial statements and has been prepared on the same basis as the audited Consolidated Financial Statements appearing elsewhere in this Annual Report on Form 10-K. (In millions, except per share amounts) Fourth Third Second First Fiscal year ended September 30, 2020 Revenue $ 755 $ 721 $ 682 $ 715 Gross profit 418 397 371 394 Operating income (loss) 74 53 (597) 15 Benefit from (provision for) income taxes 20 (20) (37) (25) Net income (loss) 37 9 (672) (54) Net income (loss) attributable to common stockholders 33 7 (673) (59) Earnings (loss) per common share - basic $ 0.40 $ 0.08 $ (7.24) $ (0.54) Earnings (loss) per common share - diluted $ 0.39 $ 0.08 $ (7.24) $ (0.54) (In millions, except per share amounts) Fourth Third Second First Fiscal year ended September 30, 2019 Revenue $ 723 $ 717 $ 709 $ 738 Gross profit 392 390 386 407 Operating income (loss) 52 (613) 38 50 (Provision for) benefit from income taxes (32) 27 6 (3) Net (loss) income (34) (633) (13) 9 Net (loss) income attributable to common stockholders (34) (633) (13) 9 Earnings (loss) per common share - basic $ (0.31) $ (5.70) $ (0.12) $ 0.08 Earnings (loss) per common share - diluted $ (0.31) $ (5.70) $ (0.12) $ 0.08

Condensed Financial Informati_2

Condensed Financial Information of Parent Company (Tables)	12 Months Ended
	Sep. 30, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheets	Avaya Holdings Corp. Parent Company Only Condensed Statements of Financial Position (In millions) As of September 30, 2020 2019 ASSETS Investment in Avaya Inc. $ 888 $ 1,604 TOTAL ASSETS $ 888 $ 1,604 LIABILITIES AND STOCKHOLDERS' EQUITY LIABILITIES Long-term debt $ 291 $ 273 Other liabilities 233 31 TOTAL LIABILITIES 524 304 Commitments and contingencies Convertible series A preferred stock; 125,000 shares issued and outstanding at September 30, 2020 and no shares issued and outstanding at September 30, 2019 128 — TOTAL STOCKHOLDERS' EQUITY 236 1,300 TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY $ 888 $ 1,604
Condensed Statements of Operations	Avaya Holdings Corp. Parent Company Only Condensed Statements of Operations (In millions, except per share amounts) Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from 2020 2019 Equity in net (loss) income of Avaya Inc. $ (616) $ (672) $ 311 $ 2,977 Selling, general and administrative (35) (3) — — Interest expense (26) (25) (3) — Other (expense) income, net (3) 29 (21) — (LOSS) INCOME BEFORE INCOME TAXES (680) (671) 287 2,977 Provision for income taxes — — — — NET (LOSS) INCOME (680) (671) 287 2,977 Less: Accretion and accrued dividends on Series A preferred stock (7) — — — NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS $ (687) $ (671) $ 287 $ 2,977 (LOSS) EARNINGS PER SHARE AVAILABLE TO COMMON STOCKHOLDERS Basic $ (7.45) $ (6.06) $ 2.61 $ 5.19 Diluted $ (7.45) $ (6.06) $ 2.58 $ 5.19 Weighted average shares outstanding Basic 92.2 110.8 109.9 497.3 Diluted 92.2 110.8 111.1 497.3
Condensed Statements of Comprehensive Income (Loss)	Avaya Holdings Corp. Parent Company Only Condensed Statements of Comprehensive (Loss) Income (In millions) Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from 2020 2019 Net (loss) income $ (680) $ (671) $ 287 $ 2,977 Equity in other comprehensive (loss) income of Avaya Inc. (72) (191) 18 658 Elimination of Predecessor Company accumulated other comprehensive loss — — — 790 Comprehensive (loss) income $ (752) $ (862) $ 305 $ 4,425
Condensed Statements of Cash Flows	Avaya Holdings Corp. Parent Company Only Condensed Statements of Cash Flows (In millions) Successor Predecessor Fiscal years ended September 30, Period from December 16, 2017 Period from 2020 2019 Net (loss) income $ (680) $ (671) $ 287 $ 2,977 Adjustments to reconcile net (loss) income to net cash used for operating activities: Equity in net loss (income) of Avaya Inc. 616 672 (311) (2,977) Share-based compensation 2 2 — — Amortization of debt issuance costs 18 17 4 — Change in fair value of emergence date warrants 3 (29) 17 — Changes in operating assets and liabilities — 9 3 — Net cash used for operating activities (41) — — — Net cash used for investing activities — — (314) — Net cash provided by financing activities 41 — 314 — Net increase (decrease) in cash and cash equivalents — — — — Cash and cash equivalents at beginning of period — — — — Cash and cash equivalents at end of period $ — $ — $ — $ —

Background and Basis of Prese_2

Background and Basis of Presentation - Narrative (Details) $ in Millions	12 Months Ended
	Sep. 30, 2020USD ($)segment	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Dec. 15, 2017USD ($)
General Disclosures [Line Items]
Cash and cash equivalents | $	$ 727	$ 752	$ 700	$ 366
Number of segments | segment	2

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Oct. 01, 2018
Schedule of Significant Accounting Policies [Line Items]
Unamortized internal use software development costs			$ 91	$ 83
Expected long-term return on assets, adjusted			2.00%
Expected long-term return on assets, difference from expected to actual			20.00%
Advertising expense	$ 9	$ 27	$ 42	39
Smoothing technique, years			five
Average Rate of Return on Plan Assets, Years			ten
Trademarks and Trade Names Member
Schedule of Significant Accounting Policies [Line Items]
Intangible asset, useful life			10 years
Accounting Standards Update 2014-09 | Retained Earnings [Member]
Schedule of Significant Accounting Policies [Line Items]
Change in accounting principle					$ 95
Software Development [Member]
Schedule of Significant Accounting Policies [Line Items]
Depreciation	$ 5	$ 31	$ 27	$ 39
Minimum
Schedule of Significant Accounting Policies [Line Items]
Amortization period of internal use software capitalization			5 years
Intangible asset, useful life			1 year
Minimum | Acquired technology and patents
Schedule of Significant Accounting Policies [Line Items]
Intangible asset, useful life			1 year
Minimum | Customer relationships and other intangibles
Schedule of Significant Accounting Policies [Line Items]
Intangible asset, useful life			1 year
Minimum | Machinery and equipment
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			2 years
Maximum
Schedule of Significant Accounting Policies [Line Items]
Amortization period of internal use software capitalization			7 years
Intangible asset, useful life			19 years
Maximum | Acquired technology and patents
Schedule of Significant Accounting Policies [Line Items]
Intangible asset, useful life			10 years
Maximum | Customer relationships and other intangibles
Schedule of Significant Accounting Policies [Line Items]
Intangible asset, useful life			19 years
Maximum | Machinery and equipment
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			10 years
Weighted Average | Acquired technology and patents
Schedule of Significant Accounting Policies [Line Items]
Intangible asset, useful life			3 years 1 month 6 days
Weighted Average | Customer relationships and other intangibles
Schedule of Significant Accounting Policies [Line Items]
Intangible asset, useful life			11 years 10 months 24 days
Weighted Average | Trademarks and Trade Names Member
Schedule of Significant Accounting Policies [Line Items]
Intangible asset, useful life			7 years 2 months 12 days
Largest Customer | Revenue from Contract with Customer | Customer Concentration Risk
Schedule of Significant Accounting Policies [Line Items]
Concentration risk			8.00%
Distributor One | Accounts Receivable | Customer Concentration Risk
Schedule of Significant Accounting Policies [Line Items]
Concentration risk, threshold			9.00%	12.00%

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2020	Oct. 01, 2019	Sep. 30, 2019	Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts Receivable, after Allowance for Credit Loss, Current	$ 275		$ 314
Restricted cash	4
Contract with Customer, Liability, Current	446		472
Goodwill	1,478		2,103	$ 2,764
Inventory, Net	54		63
Contract with Customer, Asset, Net, Current	296		187
Capitalized Contract Cost, Net, Current	115		114
Other Assets, Current	112	$ 113	115
Intangible assets, net	2,556	2,889	2,891
Property, Plant and Equipment, Net	268		255
Deferred Income Tax Assets, Net	31		35
Other Assets, Noncurrent	159		121
Other Liabilities, Current	181		158
Deferred Income Tax Liabilities, Net	38		72
Other Liabilities, Noncurrent	312	313	316
Retained Earnings (Accumulated Deficit)	(969)		(289)
Operating Lease, Right-of-Use Asset	160	190	0
Operating Lease, Liability, Current	49	51	0
Restructuring Reserve, Current	21	29	33
Operating Lease, Liability, Noncurrent	129	143	0
Business restructuring reserve, non-current portion	28	35	$ 36
Operating Lease, Liability	$ 178
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other Assets, Current		(2)
Intangible assets, net		(2)
Other Liabilities, Noncurrent		(3)
Operating Lease, Right-of-Use Asset		190
Operating Lease, Liability, Current		51
Restructuring Reserve, Current		(4)
Operating Lease, Liability, Noncurrent		143
Business restructuring reserve, non-current portion		(1)
Operating Lease, Liability		$ 194

Emergence from Voluntary Reor_2

Emergence from Voluntary Reorganization under Chapter 11 Proceedings (Details) - USD ($) $ / shares in Units, $ in Millions	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 25, 2020
Fresh-Start Adjustment [Line Items]
Repayment of debtor-in-possession financing	$ 725	$ 725	$ 0	$ 0	$ 0
Shares authorized (in shares)	605,000,000	605,000,000
Preferred stock, shares authorized				55,000,000	55,000,000
Preferred stock, par value (in usd per share)				$ 0.01	$ 0.01
Common stock, shares authorized				550,000,000	550,000,000
Common stock, par value (usd per share)				$ 0.01	$ 0.01
Common stock, shares issued	110,000,000	110,000,000		83,278,383	111,046,085
Debt face amount	$ 2,925	$ 2,925		$ 2,993	$ 3,224
Class of warrant or right, number of securities called by each warrant or right (in shares)	5,645,200	5,645,200
Class of warrant or right, exercise price of warrants or rights (in USD per share)	$ 25.55	$ 25.55
Payment to PBGC		$ 340	0	0	0
Payment of unsecured claims		$ 58	$ 0	0	$ 0
Common stock issued for GUC (in shares)	200,000	200,000			12,680
As Previously Reported
Fresh-Start Adjustment [Line Items]
Common stock, shares issued	110,000,000	110,000,000
General Unsecured Creditor Reserve
Fresh-Start Adjustment [Line Items]
Payment of unsecured claims	$ 58
Term Loan
Fresh-Start Adjustment [Line Items]
Debt face amount				$ 1,643	$ 2,874
First Lien Debt
Fresh-Start Adjustment [Line Items]
Repayments of long-term debt	$ 2,061
7% senior secured notes | First Lien Debt
Fresh-Start Adjustment [Line Items]
Interest rate, stated percentage			7.00%
9% senior secured notes | First Lien Debt
Fresh-Start Adjustment [Line Items]
Interest rate, stated percentage			9.00%
10.50% senior secured notes | Second Lien Debt
Fresh-Start Adjustment [Line Items]
Interest rate, stated percentage	10.50%	10.50%
Revolving Credit Facility
Fresh-Start Adjustment [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 300	$ 300				$ 200
Pension Plan | Avaya Inc. Pension Plan for Salaried Employees
Fresh-Start Adjustment [Line Items]
Common stock issued for PBGC (in shares)	6,100,000	6,100,000
Payment to PBGC	$ 340

Emergence from Voluntary Reor_3

Emergence from Voluntary Reorganization under Chapter 11 Proceedings - Section 363 Asset Sale (Details) - USD ($) $ in Millions	1 Months Ended		2 Months Ended	10 Months Ended	12 Months Ended
	Sep. 30, 2018	Jul. 31, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income From Transition Services Agreement, Net			$ 3	$ 5	$ 0	$ 0
Disposed of by Sale | Networking Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Lease obligation		$ 20
Escrow deposit disbursements	$ 7
Disposed of by Sale | Networking Business | Extreme Networks
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow deposit disbursements	$ 3
Extreme Networks | Disposed of by Sale | Networking Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses		70
Indemnity escrow		$ 10

Fresh Start Accounting - Narrat

Fresh Start Accounting - Narrative (Details) - USD ($)	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 25, 2020	Dec. 16, 2017
Fresh-Start Adjustment [Line Items]
Repayment of debtor-in-possession financing	$ 725,000,000	$ 725,000,000	$ 0	$ 0	$ 0
Debt maturing within one year				0	29,000,000
Debt face amount	2,925,000,000	2,925,000,000		2,993,000,000	3,224,000,000
Funding payment for Avaya represented employee pension plan		$ 49,000,000	0	0	0
Debt cancelled due to bankruptcy	5,721,000,000
Common stock issued for Predecessor debt	$ 1,509,000,000
Class of warrant or right, number of securities called by each warrant or right (in shares)	5,645,200	5,645,200
Payment to PBGC		$ 340,000,000	$ 0	0	0
Common stock issued for Pension Benefit Guaranty Corporation	$ 92,000,000	92,000,000
Goodwill	3,541,000,000	3,541,000,000
Establish Successor Goodwill	2,658,000,000	2,658,000,000					$ 2,658,000,000
Discharge of Debt
Fresh-Start Adjustment [Line Items]
Debt maturing within one year	29,000,000	29,000,000
Accounts payable	(49,000,000)	(49,000,000)
Adjustments, accounts payable, reclassification of accrued bankruptcy related professional fees	(50,000,000)	(50,000,000)
Adjustments, accounts payable, payment of bankruptcy professional fees	(3,000,000)	(3,000,000)
Adjustments, accounts payable, reinstatement of contract cure costs	4,000,000	4,000,000
Payroll and benefit obligations	23,000,000	23,000,000
Fair value adjustment to Deferred revenue	79,000,000	79,000,000
Deferred revenue	50,000,000	50,000,000
Adjustments, other liabilities, deferred revenue	29,000,000	29,000,000
Adjustments, restructuring reserve	7,000,000	7,000,000
Business restructuring reserve	3,000,000	3,000,000
Business restructuring reserve	4,000,000	4,000,000
Adjustments, liabilities subject to compromise, pension obligation	(295,000,000)	(295,000,000)
Funding payment for Avaya represented employee pension plan	49,000,000
Other post-retirement obligations	212,000,000	212,000,000
Change in other liabilities	233,000,000	233,000,000
Payment to PBGC	340,000,000
Property, plant and equipment, net	0	0
Intangible assets, net	0	0
Change in other assets	6,000,000	6,000,000
Change in other current liabilities	65,000,000	65,000,000
Revaluation of Assets
Fresh-Start Adjustment [Line Items]
Property, plant and equipment, net	116,000,000	116,000,000
Intangible assets, net	3,137,000,000	3,137,000,000
Change in other assets	(27,000,000)	(27,000,000)
Revaluation of Liabilities
Fresh-Start Adjustment [Line Items]
Accounts payable	0	0
Payroll and benefit obligations	0	0
Fair value adjustment to Deferred revenue	235,000,000	235,000,000
Deferred revenue	(341,000,000)	(341,000,000)
Business restructuring reserve	0	0
Business restructuring reserve	(4,000,000)	(4,000,000)
Other post-retirement obligations	0	0
Change in other liabilities	43,000,000	43,000,000
Change in other current liabilities	3,000,000	3,000,000
Minimum
Fresh-Start Adjustment [Line Items]
Enterprise value	5,100,000,000	5,100,000,000
Maximum
Fresh-Start Adjustment [Line Items]
Enterprise value	$ 7,100,000,000	7,100,000,000
Term Loan
Fresh-Start Adjustment [Line Items]
Debt face amount				$ 1,643,000,000	$ 2,874,000,000
First Lien Debt
Fresh-Start Adjustment [Line Items]
Common stock issued for debt (in shares)	99,300,000
Repayment of long-term debt	$ 2,061,000,000
Second Lien Debt
Fresh-Start Adjustment [Line Items]
Common stock issued for debt (in shares)	4,400,000
Common stock issued for Predecessor debt	$ 67,000,000
Term Loan Credit Agreement due December 15, 2024 | Term Loan | Discharge of Debt
Fresh-Start Adjustment [Line Items]
Debt face amount	2,925,000,000	2,925,000,000
Revolving Credit Facility
Fresh-Start Adjustment [Line Items]
Line of Credit Facility, Current Borrowing Capacity	300,000,000	300,000,000				$ 200,000,000
Warrants
Fresh-Start Adjustment [Line Items]
Fair value of warrant liability	17,000,000	$ 17,000,000
Pension Plan | Avaya Inc. Pension Plan for Salaried Employees
Fresh-Start Adjustment [Line Items]
Payment to PBGC	$ 340,000,000
Common stock issued for PBGC (in shares)	6,100,000	6,100,000
Common stock issued for Pension Benefit Guaranty Corporation	$ 92,000,000	$ 92,000,000

Fresh Start Accounting - Enterp

Fresh Start Accounting - Enterprise Value To The Estimated Fair Value Of The Successor Common Stock (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 30, 2020	Sep. 30, 2019	Dec. 16, 2017	Dec. 15, 2017
Plus:
Cash and cash equivalents			$ 366	$ 366
Less:
Minimum cash required for operations				(120)
Fair value of Term Loan Credit Agreement				(2,896)
Fair value of capitalized leases				(20)
Fair value of pension and other post-retirement obligations, net of tax				856
Change in net deferred tax liabilities from reorganization				510
Fair value of Successor Emergence Date Warrants				(17)
Fair value of Successor common stock			$ 1,668	$ 1,668
Shares issued at December 15, 2017 (in shares)	83,278,383	111,046,085		110,000,000
Per share value (usd per share)				$ 15.16
Debt, fair value, percent of par				99.00%
Post-retirement Benefits
Less:
Rate of return on plan assets				5.90%
Discount rate				3.77%
U.S. | Pension Plan
Less:
Rate of return on plan assets				7.75%
Discount rate	2.50%	3.09%		3.70%
U.S. | Post-retirement Benefits
Less:
Discount rate	2.69%	3.17%
Non-US | Pension Plan
Less:
Rate of return on plan assets				3.80%
Discount rate	0.86%	0.87%		1.52%
As Previously Reported
Fresh-Start Adjustment [Line Items]
Enterprise value				$ 5,721
Less:
Shares issued at December 15, 2017 (in shares)				110,000,000

Fresh Start Accounting - Ente_2

Fresh Start Accounting - Enterprise Value To The Estimated Reorganization Value (Details) $ in Millions	Dec. 15, 2017USD ($)
Plus:
Non-debt current liabilities	$ 955
Non-debt non-current liabilities	2,090
Excess cash and cash equivalents	246
Less:
Pension and other post-retirement obligations, net of deferred taxes	856
Fair value of capitalized leases	(20)
Change in net deferred tax liabilities from reorganization	510
Emergence Date Warrants issued	(17)
Reorganization value of Successor assets	7,609
As Previously Reported
Enterprise value	$ 5,721

Fresh Start Accounting - Balanc

Fresh Start Accounting - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 15, 2017	Dec. 16, 2017
Current assets:
Cash and cash equivalents	$ 770
Accounts receivable, net	497
Inventory	90
Other current assets	374
TOTAL CURRENT ASSETS	1,731
Property, plant and equipment, net	194
Deferred income taxes, net	0
Intangible assets, net	298
Goodwill	3,541
Other assets	70
TOTAL ASSETS	5,834
Current liabilities:
Debt maturing within one year	725
Accounts payable	325
Payroll and benefit obligations	123
Deferred revenue	627
Business restructuring reserve	35
Other current liabilities	97
TOTAL CURRENT LIABILITIES	1,932
Non-current liabilities:
Long-term debt, net of current portion	0
Pension obligations	539
Other post-retirement obligations	0
Deferred income taxes, net	28
Business restructuring reserve	26
Other liabilities	180
TOTAL NON-CURRENT LIABILITIES	773
LIABILITIES SUBJECT TO COMPROMISE	7,585
TOTAL LIABILITIES	10,290
Commitments and contingencies
Equity awards on redeemable shares	6
STOCKHOLDERS' (DEFICIT) EQUITY
(Accumulated deficit) retained earnings	(5,978)
Accumulated other comprehensive (loss) income	(1,454)
TOTAL STOCKHOLDERS' (DEFICIT) EQUITY	(5,045)
TOTAL LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY	5,834
Current assets:
Cash and cash equivalents	366	$ 366
Accounts receivable, net		391
Inventory		119
Other current assets		250
TOTAL CURRENT ASSETS		1,126
Property, plant and equipment, net	310	310
Deferred income taxes, net		31
Intangible assets, net	3,435	3,435
Goodwill	2,658	2,658
Other assets		49
TOTAL ASSETS		7,609
Current liabilities:
Debt maturing within one year		29
Accounts payable		276
Payroll and benefit obligations		146
Deferred revenue		336
Business restructuring reserve		38
Other current liabilities		159
TOTAL CURRENT LIABILITIES		984
Non-current liabilities:
Long-term debt, net of current portion		2,867
Pension obligations		785
Other post-retirement obligations		212
Deferred income taxes, net		689
Business restructuring reserve		34
Other liabilities		370
TOTAL NON-CURRENT LIABILITIES		4,957
LIABILITIES SUBJECT TO COMPROMISE	0	0
TOTAL LIABILITIES		5,941
Commitments and contingencies
Equity awards on redeemable shares		0
STOCKHOLDERS' (DEFICIT) EQUITY
(Accumulated deficit) retained earnings		0
Accumulated other comprehensive (loss) income		0
TOTAL STOCKHOLDERS' (DEFICIT) EQUITY	1,668	1,668
TOTAL LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY		7,609
Common stock issued for Predecessor debt	1,509
Common stock issued for Pension Benefit Guaranty Corporation	92
Financial Designation, Successor
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock	0
Additional paid-in capital	0
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock		1
Additional paid-in capital		1,667
Financial Designation, Predecessor
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock	0
Additional paid-in capital	2,387
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock		0
Additional paid-in capital		0
Pension Plan | Avaya Inc. Pension Plan for Salaried Employees
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock issued for Pension Benefit Guaranty Corporation	92
Warrants
STOCKHOLDERS' (DEFICIT) EQUITY
Fair value of warrant liability	17
Second Lien Debt
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock issued for Predecessor debt	67
Discharge of Debt
Current assets:
Cash and cash equivalents	(404)
Accounts receivable, net	0
Inventory	0
Other current assets	(58)
TOTAL CURRENT ASSETS	(462)
Property, plant and equipment, net	0
Deferred income taxes, net	48
Intangible assets, net	0
Goodwill	0
Other assets	6
TOTAL ASSETS	(408)
Current liabilities:
Debt maturing within one year	(696)
Accounts payable	(49)
Payroll and benefit obligations	23
Deferred revenue	50
Business restructuring reserve	3
Other current liabilities	65
TOTAL CURRENT LIABILITIES	(604)
Non-current liabilities:
Long-term debt, net of current portion	2,771
Pension obligations	246
Other post-retirement obligations	212
Deferred income taxes, net	113
Business restructuring reserve	(4)
Other liabilities	233
TOTAL NON-CURRENT LIABILITIES	3,579
LIABILITIES SUBJECT TO COMPROMISE	(7,585)
TOTAL LIABILITIES	(4,610)
Commitments and contingencies
Equity awards on redeemable shares	(6)
STOCKHOLDERS' (DEFICIT) EQUITY
(Accumulated deficit) retained earnings	4,846
Accumulated other comprehensive (loss) income	664
TOTAL STOCKHOLDERS' (DEFICIT) EQUITY	4,791
TOTAL LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY	(408)
Discharge of Debt | Financial Designation, Successor
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock	1
Additional paid-in capital	1,667
Discharge of Debt | Financial Designation, Predecessor
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock	0
Additional paid-in capital	(2,387)
Revaluation of Assets
Current assets:
Cash and cash equivalents	0
Accounts receivable, net	(106)
Inventory	29
Other current assets	(66)
TOTAL CURRENT ASSETS	(143)
Property, plant and equipment, net	116
Deferred income taxes, net	(17)
Intangible assets, net	3,137
Goodwill	(883)
Other assets	(27)
TOTAL ASSETS	2,183
Revaluation of Liabilities
Current liabilities:
Debt maturing within one year	0
Accounts payable	0
Payroll and benefit obligations	0
Deferred revenue	(341)
Business restructuring reserve	0
Other current liabilities	3
TOTAL CURRENT LIABILITIES	(344)
Non-current liabilities:
Long-term debt, net of current portion	96
Pension obligations	0
Other post-retirement obligations	0
Deferred income taxes, net	548
Business restructuring reserve	4
Other liabilities	43
TOTAL NON-CURRENT LIABILITIES	605
LIABILITIES SUBJECT TO COMPROMISE	0
TOTAL LIABILITIES	261
Exchange of Stock for Stock
Commitments and contingencies
Equity awards on redeemable shares	0
STOCKHOLDERS' (DEFICIT) EQUITY
(Accumulated deficit) retained earnings	1,132
Accumulated other comprehensive (loss) income	790
TOTAL STOCKHOLDERS' (DEFICIT) EQUITY	1,922
TOTAL LIABILITIES AND STOCKHOLDERS' (DEFICIT) EQUITY	2,183
Exchange of Stock for Stock | Financial Designation, Successor
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock	0
Additional paid-in capital	0
Exchange of Stock for Stock | Financial Designation, Predecessor
STOCKHOLDERS' (DEFICIT) EQUITY
Common stock	0
Additional paid-in capital	0
Series B Preferred Stock
Commitments and contingencies
Preferred stock:	397
Commitments and contingencies
Preferred stock:		0
Series B Preferred Stock | Discharge of Debt
Commitments and contingencies
Preferred stock:	(397)
Series B Preferred Stock | Exchange of Stock for Stock
Commitments and contingencies
Preferred stock:	0
Series A Preferred Stock
Commitments and contingencies
Preferred stock:	186
Commitments and contingencies
Preferred stock:		$ 0
Series A Preferred Stock | Discharge of Debt
Commitments and contingencies
Preferred stock:	(186)
Series A Preferred Stock | Exchange of Stock for Stock
Commitments and contingencies
Preferred stock:	$ 0

Fresh Start Accounting - Source

Fresh Start Accounting - Sources And Uses Of Cash (Details) - USD ($) $ in Millions	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Uses:
Cash paid to PBGC		$ (340)	$ 0	$ 0	$ 0
Funding payment for Avaya represented employee pension plan		(49)	0	0	0
Payment for general unsecured claims		(58)	$ 0	$ 0	$ 0
Discharge of Debt
Sources:
Proceeds from Term Loan Credit Agreement, net of original issue discount	$ 2,896
Release of restricted cash	76	76
Total sources of cash	2,972	2,972
Uses:
Repayment of DIP Credit Agreement	(725)
Payment of DIP Credit Agreement accrued interest	(1)
Cash paid to Predecessor first lien debt-holders	(2,061)
Cash paid to PBGC	(340)
Payment for professional fees escrow account	(56)
Funding payment for Avaya represented employee pension plan	(49)
Payment of accrued professional and administrative fees	(27)
Costs incurred for Term Loan Credit Agreement and ABL Credit Agreement	(59)
Payment for general unsecured claims	(58)
Total uses of cash	(3,376)	(3,376)
Net uses of cash	$ (404)	$ (404)

Fresh Start Accounting - Other

Fresh Start Accounting - Other Current Assets (Details) - USD ($) $ in Millions	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Fresh-Start Adjustment [Line Items]
Payment of unsecured claims		$ (58)	$ 0	$ 0	$ 0
Discharge of Debt
Fresh-Start Adjustment [Line Items]
Fresh-Start Adjustment, Increase (Decrease), Release Of Restricted Cash	$ (76)	(76)
Fresh-Start Adjustment, Increase (Decrease), Reclassification Of Prepaid Debt Issuance Costs	(42)	(42)
Fresh-Start Adjustment, Increase (Decrease), Payment Of Debt Financing Fees	5	5
Fresh-Start Adjustment, Increase (Decrease), Restricted Cash For Bankruptcy Related Professional Fees	55	55
Fresh-Start Adjustment, Increase (Decrease), Prepaid and Other Current Assets	(58)	$ (58)
Payment of unsecured claims	$ (58)

Fresh Start Accounting - Othe_2

Fresh Start Accounting - Other Current Liabilities (Details) - Discharge of Debt $ in Millions	Dec. 15, 2017USD ($)
Fresh-Start Adjustment [Line Items]
Reclassification of accrued bankruptcy related professional fees	$ 50
Reinstatement of other current liabilities	16
Payment of accrued interest on the DIP Credit Agreement	(1)
Total other current liabilities	$ 65

Fresh Start Accounting - Exit F

Fresh Start Accounting - Exit Financing (Details) - USD ($)	Sep. 30, 2020	Sep. 30, 2019	Dec. 15, 2017
Fresh-Start Adjustment [Line Items]
Term Loan Credit Agreement	$ 2,993,000,000	$ 3,224,000,000	$ 2,925,000,000
Less:
Current portion of Long-term debt	0	(29,000,000)
Discharge of Debt
Less:
Discount			(29,000,000)
Upfront and underwriting fees			(54,000,000)
Cash received upon emergence from bankruptcy			2,842,000,000
Reclassification of debt issuance costs incurred prior to emergence from bankruptcy			(42,000,000)
Current portion of Long-term debt			(29,000,000)
Long-term debt, net of current portion			2,771,000,000
Term Loan
Fresh-Start Adjustment [Line Items]
Term Loan Credit Agreement	$ 1,643,000,000	$ 2,874,000,000
Term Loan | Term Loan Credit Agreement due December 15, 2024 | Discharge of Debt
Fresh-Start Adjustment [Line Items]
Term Loan Credit Agreement			$ 2,925,000,000

Fresh Start Accounting - Liabil

Fresh Start Accounting - Liabilities Subject to Compromise (Details) - USD ($) $ in Millions	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Dec. 16, 2017
Fresh-Start Adjustment [Line Items]
Preconfirmation, Liabilities Subject to Compromise	$ 7,585	$ 7,585
Liabilities Subject To Compromise, Amounts Reinstated [Abstract]
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Liabilities Reinstated	(941)	(941)
LIABILITIES SUBJECT TO COMPROMISE	0	0				$ 0
Payment of unsecured claims		58	$ 0	$ 0	$ 0
Gain On Settlement of Liabilities Subject To Compromise [Abstract]
Debtor Reorganization Items, Gain (Loss) On Settlement Of Liabilities Subject To Compromise, First Lien Debt		711
Debtor Reorganization Items, Gain (Loss) On Settlement Of Liabilities Subject To Compromise, Second Lien Debt		1,356
Debtor Reorganization Items, Gain (Loss) On Settlement Of Liabilities Subject To Compromise, Pension Plan For Salaried Employees		(516)
Debtor Reorganization Items, Gain (Loss) On Settlement Of Liabilities Subject To Compromise, General Unsecured Creditor's Claims		227
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net	1,778	1,778	$ 0	$ 0	$ 0
Discharge of Debt
Liabilities Subject To Compromise, Less Amounts Settled Per Plan of Reorganization [Abstract]
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, First Lien Debt Settled	(4,281)	(4,281)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Second Lien Debt Settled	(1,440)	(1,440)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Pension Settled	(620)	(620)
Liabilities Subject To Compromise, Amounts Reinstated [Abstract]
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Accounts Payable	(4)	(4)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Employee Related Liabilities	(23)	(23)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Deferred Revenue	(50)	(50)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Restructuring Reserve	(7)	(7)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Other Current Liabilities	(16)	(16)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Pension Obligations	(295)	(295)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Other Post-Retirement Obligation	(212)	(212)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Deferred Income Taxes, Net	(118)	(118)
Fresh-Start Adjustment, Increase (Decrease), Liabilities Subject to Compromise, Other Liabilities	(216)	(216)
General unsecured credit claims	(303)	(303)
Payment of unsecured claims	58
Gain On Settlement of Liabilities Subject To Compromise [Abstract]
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net		$ 1,778
General Unsecured Creditor Reserve
Liabilities Subject To Compromise, Amounts Reinstated [Abstract]
Payment of unsecured claims	$ 58

Fresh Start Accounting - Accumu

Fresh Start Accounting - Accumulated Deficit (Details) - USD ($) $ in Millions	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Fresh-Start Adjustment [Line Items]
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net	$ 1,778	$ 1,778	$ 0	$ 0	$ 0
Discharge of Debt
Fresh-Start Adjustment [Line Items]
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net		1,778
Fresh-Start Adjustment, Increase (Decrease), Retained Earnings (Deficit), Expense For Certain Professional Fees	(26)	(26)
Fresh-Start Adjustment, Increase (Decrease), Retained Earnings (Deficit), Benefit From Income Taxes	118	118
Fresh-Start Adjustment, Increase (Decrease), Retained Earnings (Deficit), Cancellation Of Equity Awards	6	6
Fresh-Start Adjustment, Increase (Decrease), Retained Earnings (Deficit), Cancellation Of Common Stock	2,387	2,387
Fresh-Start Adjustment, Increase (Decrease), Retained Earnings (Deficit)	4,846	4,846
Series B Preferred Stock | Discharge of Debt
Fresh-Start Adjustment [Line Items]
Cancellation of Predecessor Preferred stock	397	397
Series A Preferred Stock | Discharge of Debt
Fresh-Start Adjustment [Line Items]
Cancellation of Predecessor Preferred stock	$ 186	$ 186

Fresh Start Accounting - Proper

Fresh Start Accounting - Property, Plant and Equipment (Details) - USD ($) $ in Millions	Dec. 16, 2017	Dec. 15, 2017
Fresh-Start Adjustment [Line Items]
Postconfirmation, Accumulated Depreciation and Amortization		$ 0
Postconfirmation, Property and Equipment, Net, Total	$ 310	310
Building and Building Improvements [Member]
Fresh-Start Adjustment [Line Items]
Postconfirmation, Property and Equipment, Gross		82
Machinery and equipment
Fresh-Start Adjustment [Line Items]
Postconfirmation, Property and Equipment, Gross		38
Assets Leased to Others [Member]
Fresh-Start Adjustment [Line Items]
Postconfirmation, Property and Equipment, Gross		85
Assets under construction
Fresh-Start Adjustment [Line Items]
Postconfirmation, Property and Equipment, Gross		13
Software Development [Member]
Fresh-Start Adjustment [Line Items]
Postconfirmation, Property and Equipment, Gross		$ 92

Fresh Start Accounting - Intang

Fresh Start Accounting - Intangible Assets (Details) - USD ($) $ in Millions	Dec. 16, 2017	Dec. 15, 2017
Fresh-Start Adjustment [Line Items]
Establish Successor Intangible assets	$ 3,435	$ 3,435
Intangible assets, net		298
Revaluation of Assets
Fresh-Start Adjustment [Line Items]
Intangible assets, net		3,137
Customer relationships and other intangible assets
Fresh-Start Adjustment [Line Items]
Establish Successor Intangible assets		2,155
Intangible assets, net		96
Customer relationships and other intangible assets | Revaluation of Assets
Fresh-Start Adjustment [Line Items]
Intangible assets, net		2,059
Technology and patents
Fresh-Start Adjustment [Line Items]
Establish Successor Intangible assets		905
Intangible assets, net		12
Technology and patents | Revaluation of Assets
Fresh-Start Adjustment [Line Items]
Intangible assets, net		893
Trademarks and trade names | Trademarks and trade names
Fresh-Start Adjustment [Line Items]
Establish Successor Intangible assets		375
Intangible assets, net		190
Trademarks and trade names | Trademarks and trade names | Revaluation of Assets
Fresh-Start Adjustment [Line Items]
Intangible assets, net		$ 185

Fresh Start Accounting - Goodwi

Fresh Start Accounting - Goodwill (Details) - USD ($) $ in Millions	Dec. 16, 2017	Dec. 15, 2017
Reorganization value of Successor Company	$ 7,609
Less: Fair value of Successor Company assets	(4,951)
Reorganization value of Successor Company assets in excess of fair value - Goodwill	$ 2,658	$ 2,658

Fresh Start Accounting - Fresh

Fresh Start Accounting - Fresh Start Adjustments (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Dec. 16, 2017
Fresh-Start Adjustment [Line Items]
Eliminate Predecessor Intangible assets	$ (298)
Eliminate Predecessor Goodwill	(3,541)
Establish Successor Intangible assets	3,435				$ 3,435
Establish Successor Goodwill	2,658				$ 2,658
Net gain on fresh start adjustments	1,697	$ 0	$ 0	$ 0
Tax impact of fresh start adjustments	(565)
Gain on fresh start accounting, net	1,132
Revaluation of Assets
Fresh-Start Adjustment [Line Items]
Fair value adjustment to Inventory	29
Fair value adjustment to Other current assets	(66)
Fair value adjustment to Property, plant and equipment	116
Fair value adjustment to Other assets	(27)
Revaluation of Liabilities
Fresh-Start Adjustment [Line Items]
Fair value adjustment to Deferred revenue	(235)
Fair value adjustment to Business restructuring reserves	4
Fair value adjustment to Other current liabilities	(3)
Fair value adjustment to Long-term debt	(96)
Fair value adjustment to Other liabilities	(43)
Exchange of Stock for Stock
Fresh-Start Adjustment [Line Items]
Release Predecessor Accumulated comprehensive loss	$ (790)

Revenue Recognition - Impact of

Revenue Recognition - Impact of Adoption (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2017	Oct. 01, 2019
ASSETS
Accounts receivable, net		$ 275				$ 314					$ 275	$ 314
Inventory		54				63					54	63
Contract assets		296				187					296	187
Contract costs		115				114					115	114
Other current assets		112				115					112	115		$ 113
Property, plant and equipment, net		268				255					268	255
Deferred income taxes, net		31				35					31	35
Other assets		159				121					159	121
Accounts Payable, Current		242				291					242	291
LIABILITIES
Contract liabilities		446				472					446	472
Other current liabilities		181				158					181	158
Deferred income taxes, net		38				72					38	72
Other liabilities		312				316					312	316		$ 313
STOCKHOLDERS' EQUITY
Retained Earnings (Accumulated Deficit)		(969)				(289)					(969)	(289)
REVENUE
Revenue	$ (604)	(755)	$ (721)	$ (682)	$ (715)	(723)	$ (717)	$ (709)	$ (738)	$ (2,247)	(2,873)	(2,887)
COSTS
Cost of Revenue	242									1,104	1,293	1,312
GROSS PROFIT	(362)	(418)	(397)	(371)	(394)	(392)	(390)	(386)	(407)	(1,143)	(1,580)	(1,575)
OPERATING EXPENSES
Selling, general and administrative	(264)									(888)	(1,013)	(1,001)
Research and development	(38)									(172)	(207)	(204)
Amortization of intangible assets	(10)									(127)	(161)	(162)
Restructuring charges, net	(14)									(81)	(30)	(22)
Total operating Expenses	(326)									(1,268)	(2,035)	(2,048)
Operating Income (Loss) [Abstract]
OPERATING INCOME	(36)	(74)	(53)	597	(15)	(52)	613	(38)	(50)	125	455	473
Interest expense	(14)									(169)	(226)	(237)
Other income (expense), net	2									(35)	(63)	(41)
(LOSS) INCOME BEFORE INCOME TAXES	3,436									(259)	(618)	(669)
(Provision for) benefit from income taxes	459	(20)	20	37	25	32	(27)	(6)	3	(546)	62	2
Net (loss) income	2,977	$ 37	$ 9	$ (672)	$ (54)	$ (34)	$ (633)	$ (13)	$ 9	287	(680)	(671)	$ 2,977
Products
REVENUE
Revenue	(253)									(989)	(1,073)	(1,222)
COSTS
Total Cost of Goods and Services	(84)									(372)	(405)	(442)
Amortization of technology intangible assets	(3)									(135)	(174)	(174)
Services
REVENUE
Revenue	(351)									(1,258)	(1,800)	(1,665)
COSTS
Total Cost of Goods and Services	$ (155)									$ (597)	$ (714)	$ (696)

Revenue Recognition - Narrative

Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Capitalized Contract Cost to Obtain a Contract, Amortization	$ 156	$ 103
Capitalized Contract Cost to Fulfill, Amortization	52	50
Revenue recognized that was previously recorded as a contract liability	546	537
Revenue, Remaining Performance Obligation, Amount	2,400
Change in Contract with Customer, Liability	269
Increase (Decrease) In Contract With Customer, Asset, Current	109
Increase (Decrease) In Contract With Customer, Asset, Noncurrent	55
Change in Contract with Customer, Asset	164
Increase (Decrease) In Capitalized Contract Cost To Obtain, Net, Current	3
Increase (Decrease) In Capitalized Contract Cost to Obtain, Net, Noncurrent	(5)
Increase (Decrease) In Capitalized Contract Cost To Obtain, Net	(2)
Increase (Decrease) In Capitalized Contract Cost To Fulfill, Net	(2)
Increase (Decrease) In Contract with Customer, Liability, Current	(26)
Increase (Decrease) In Contract with Customer, Liability, Noncurrent	295
Selling, General and Administrative Expenses
Disaggregation of Revenue [Line Items]
Capitalized Contract Cost to Obtain a Contract, Amortization	152	100
Cost of Sales [Member]
Disaggregation of Revenue [Line Items]
Capitalized Contract Cost to Obtain a Contract, Amortization	4	$ 3
Capitalized Contract Cost to Fulfill, Amortization	48
Reduction to Revenue [Member]
Disaggregation of Revenue [Line Items]
Capitalized Contract Cost to Fulfill, Amortization	$ 4

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
REVENUE	$ 604	$ 755	$ 721	$ 682	$ 715	$ 723	$ 717	$ 709	$ 738	$ 2,247	$ 2,873	$ 2,887
U.S.
Disaggregation of Revenue [Line Items]
REVENUE	331									1,184	1,640	1,553
Asia Pacific
Disaggregation of Revenue [Line Items]
REVENUE	57									256	296	327
Products & Solutions
Disaggregation of Revenue [Line Items]
REVENUE											1,074	1,228
Products & Solutions | U.S.
Disaggregation of Revenue [Line Items]
REVENUE											546	585
Products & Solutions | International
Disaggregation of Revenue [Line Items]
REVENUE											528	643
Products & Solutions | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
REVENUE											327	381
Products & Solutions | Asia Pacific
Disaggregation of Revenue [Line Items]
REVENUE											122	155
Products & Solutions | Americas International - Canada and Latin America
Disaggregation of Revenue [Line Items]
REVENUE											79	107
Services
Disaggregation of Revenue [Line Items]
REVENUE											1,805	1,680
Services | U.S.
Disaggregation of Revenue [Line Items]
REVENUE											1,097	981
Services | International
Disaggregation of Revenue [Line Items]
REVENUE											708	699
Services | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
REVENUE											389	375
Services | Asia Pacific
Disaggregation of Revenue [Line Items]
REVENUE											175	175
Services | Americas International - Canada and Latin America
Disaggregation of Revenue [Line Items]
REVENUE											144	149
Unallocated
Disaggregation of Revenue [Line Items]
REVENUE											(6)	(21)
Operating Segments [Member] | Products & Solutions
Disaggregation of Revenue [Line Items]
REVENUE	253									1,052	1,074	1,228
Operating Segments [Member] | Services
Disaggregation of Revenue [Line Items]
REVENUE	351									1,401	1,805	1,680
Unallocated | U.S.
Disaggregation of Revenue [Line Items]
REVENUE											(3)	(13)
Unallocated | International
Disaggregation of Revenue [Line Items]
REVENUE											(3)	(8)
Unallocated | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
REVENUE											(2)	(3)
Unallocated | Asia Pacific
Disaggregation of Revenue [Line Items]
REVENUE											(1)	(3)
Unallocated | Americas International - Canada and Latin America
Disaggregation of Revenue [Line Items]
REVENUE											0	(2)
Unallocated | Unallocated
Disaggregation of Revenue [Line Items]
REVENUE	$ 0									$ (206)	$ (6)	$ (21)

Revenue Recognition - Transacti

Revenue Recognition - Transaction Price Allocated to the Remaining Performance Obligations (Details) $ in Billions	Sep. 30, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 2.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Percentage	57.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Percentage	26.00%
Maximum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	24 months
Minimum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	13 months

Revenue Recognition - Contract

Revenue Recognition - Contract Assets and Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Contract with Customer, Liability, Revenue Recognized	$ 546	$ 537
Accounts receivable, net
Accounts receivable, net	275	314
Increase (decrease) in accounts receivable, net	(39)
Contract assets:
Contract with Customer, Asset, Net, Current	296	187
Contract assets, non-current	71	16
Change in Contract with Customer, Asset	164
Total contract assets	367	203
Cost of obtaining a contract:
Cost of obtaining a contract, current	92	89
Cost of obtaining a contract, non-current	40	45
Total cost of obtaining a contract	132	134
Cost to fulfill a contract:
Cost incurred to fulfill a contract, current	23	25
Contract liabilities:
Contract with Customer, Liability, Current	446	472
Contract liabilities, non-current	373	78
Increase (Decrease) In Contract With Customer, Asset, Current	109
Increase (Decrease) In Contract With Customer, Asset, Noncurrent	55
Increase (Decrease) In Capitalized Contract Cost To Obtain, Net, Current	3
Increase (Decrease) In Capitalized Contract Cost to Obtain, Net, Noncurrent	(5)
Increase (Decrease) In Capitalized Contract Cost To Obtain, Net	(2)
Increase (Decrease) In Capitalized Contract Cost To Fulfill, Net	(2)
Increase (Decrease) In Contract with Customer, Liability, Current	(26)
Increase (Decrease) In Contract with Customer, Liability, Noncurrent	295
Change in Contract with Customer, Liability	269
Total contract liabilities	819	550
Capitalized Contract Cost to Obtain a Contract, Amortization	156	103
Capitalized Contract Cost to Fulfill, Amortization	52	50
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 1	$ 0

Leases, Codification Topic 84_2

Leases, Codification Topic 842 (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating Lease, Cost			$ 67
Short-term Lease, Cost			5
Variable Lease, Cost			17
Finance Lease, Right-of-Use Asset, Amortization			4
Sublease Income	$ 0	$ 0	5	$ 0
Lease, Cost			88
Condensed Balance Sheet Statements, Captions [Line Items]
Lessee, Operating Lease, Liability, to be Paid, Year Two			58
Lessee, Operating Lease, Liability, to be Paid, Year Three			49
Lessee, Operating Lease, Liability, to be Paid, Year Four			36
Lessee, Operating Lease, Liability, to be Paid, Year Five			25
Lessee, Operating Lease, Liability, Payments, Due Year Six			14
Lessee, Operating Lease, Liability, Payments, Due After Year Six			22
Lessee, Operating Lease, Liability, to be Paid			204
Lessee, Operating Lease, Liability, Undiscounted Excess Amount			(26)
Operating Lease, Liability			$ 178
Operating Lease, Weighted Average Remaining Lease Term			4 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent			6.10%
Finance Lease, Liability, to be Paid, Year Two			$ 9
Finance Lease, Liability, to be Paid, Year Three			4
Finance Lease, Liability, to be Paid, Year Four			3
Finance Lease, Liability, to be Paid, Year Five			2
Finance Lease, Liability, Payments, Due Year Six			0
Finance Lease, Liability, Payments, Due After Year Six			0
Finance Lease, Liability, Payment, Due			18
Finance Lease, Liability, Undiscounted Excess Amount			(1)
Finance Lease, Liability			$ 17
Finance Lease, Weighted Average Remaining Lease Term			2 years 8 months 12 days
Finance Lease, Weighted Average Discount Rate, Percent			5.40%
2019				51
2019				12
2020				6
2020				39
2021				2
2021				33
2022				0
2022				22
Capital Leases, Future Minimum Payments Due in Five Years				0
2023				17
Capital Leases, Future Minimum Payments Due Thereafter				0
Operating Leases, Future Minimum Payments, Due Thereafter				29
Capital Leases, Future Minimum Payments Due				20
Operating Leases, Future Minimum Payments Due				191
Capital Leases, Future Minimum Payments, Interest Included in Payments				(1)
Capital lease obligations				19
Avaya Private Cloud Services Business | Sale Lease Back Transaction Member [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Capital lease obligations			$ 5	13
Property, Plant and Equipment
Condensed Balance Sheet Statements, Captions [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization			12
Other current liabilities
Condensed Balance Sheet Statements, Captions [Line Items]
Finance Lease, Liability, Current			8
Capital lease obligations				11
Other liabilities
Condensed Balance Sheet Statements, Captions [Line Items]
Finance Lease, Liability, Noncurrent			$ 9
Capital lease obligations				$ 8

Business Combinations (Details)

Business Combinations (Details) $ / shares in Units, $ in Millions	Jun. 11, 2018	Mar. 09, 2018USD ($)	Dec. 15, 2017USD ($)	Sep. 30, 2020USD ($)$ / sharesshares	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)$ / sharesshares	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2019USD ($)$ / sharesshares	Oct. 03, 2019USD ($)
Business Acquisition [Line Items]
Goodwill				$ 1,478				$ 2,103				$ 2,764	$ 1,478	$ 2,103
Impairment charges														2
Revenue from Contract with Customer, Excluding Assessed Tax			$ 604	755	$ 721	$ 682	$ 715	723	$ 717	$ 709	$ 738	2,247	2,873	2,887
Operating Income (Loss)			36	74	$ 53	$ (597)	$ 15	52	$ (613)	$ 38	$ 50	(125)	(455)	(473)
Payments to Acquire Investments			0									0	0	10
Investment Owned, Balance, Principal Amount				$ 10									$ 10
Investment Interest Rate				8.00%									8.00%
Debt Instrument, Convertible, Conversion Ratio	36.0295												0.273
Debt Securities, Available-for-sale								$ 10						10
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net			0									0	$ 10	$ 0
Proceeds From Strategic Partnerships															$ 375
Proceeds From Strategic Partnerships, Share Value Received															361
Proceeds From Strategic Partnership, Cash Portion Received															$ 14
Strategic Partnership Transactions, Realized Gain (Loss)													$ 59
Preferred stock, par value (in usd per share) | $ / shares				$ 0.01				$ 0.01					$ 0.01	$ 0.01
Preferred shares issued | shares				125,000									125,000
Proceeds from Issuance of Preferred Stock and Preference Stock			$ 0									0	$ 121	$ 0
Preferred Stock, Dividend Rate, Percentage													3.00%
Series A Preferred Stock
Business Acquisition [Line Items]
Preferred stock, par value (in usd per share) | $ / shares				$ 1,000									$ 1,000
Preferred shares issued | shares				125,000				0					125,000	0
Proceeds from Issuance of Preferred Stock and Preference Stock													$ 125
Spoken
Business Acquisition [Line Items]
Purchase price		$ 172
Cash considerations		157
Contingent consideration		14
Business Combination, Contingent Consideration, Payment													5	$ 11
Net payable to company in settlement of contingent consideration		1
Goodwill		117
Net liabilities acquired		9
Fair value of intangible assets acquired		$ 64
Acquisition related costs												3
Compensation expense related to acquisition												$ 7
Estimate of Fair Value Measurement | Spoken
Business Acquisition [Line Items]
Performance targets		three
Former Owners and Employees | Spoken
Business Acquisition [Line Items]
Contingent consideration		$ 16
Earn-out Bonuses [Member] | Spoken
Business Acquisition [Line Items]
Contingent consideration		4
Business Combination, Contingent Consideration, Payment													$ 2	2
Technology-Based Intangible Assets | Spoken
Business Acquisition [Line Items]
Acquired intangible assets		$ 56
Acquired intangible assets, weighted average useful life		4 years 10 months 24 days
In Process Research and Development [Member] | Spoken
Business Acquisition [Line Items]
Acquired intangible assets								$ 3						$ 3
In Process Research and Development [Member] | Spoken
Business Acquisition [Line Items]
Acquired intangible assets		$ 5
Acquired intangible assets, weighted average useful life													4 years 2 months 12 days
Customer relationships and other intangibles | Spoken
Business Acquisition [Line Items]
Acquired intangible assets		$ 3
Acquired intangible assets, weighted average useful life		7 years 6 months

Goodwill - Schedule of Goodwill

Goodwill - Schedule of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Goodwill [Line Items]
Cost	$ 2,759	$ 2,760	$ 2,764
Accumulated Impairment	(1,281)	(657)	0
Goodwill [Roll Forward]
Goodwill, Beginning Balance	2,103	2,764
Impairment loss	(624)	(657)
Goodwill, Foreign Currency Translation Gain (Loss)	0	(2)
Goodwill, Ending Balance	1,478	2,103
Goodwill, Other Increase (Decrease)	(1)	(2)
Products & Solutions
Goodwill [Line Items]
Cost	1,281	1,282	1,283
Accumulated Impairment	(1,281)	(657)	0
Goodwill [Roll Forward]
Goodwill, Beginning Balance	625	1,283
Impairment loss	(624)	(657)
Goodwill, Foreign Currency Translation Gain (Loss)	(1)	(1)
Goodwill, Ending Balance	0	625
Goodwill, Other Increase (Decrease)	0	0
Services
Goodwill [Line Items]
Cost	1,478	1,478	1,481
Accumulated Impairment	0	0	$ 0
Goodwill [Roll Forward]
Goodwill, Beginning Balance	1,478	1,481
Impairment loss	0	0
Goodwill, Foreign Currency Translation Gain (Loss)	1	(1)
Goodwill, Ending Balance	1,478	1,478
Goodwill, Other Increase (Decrease)	$ (1)	$ (2)

Goodwill - Narrative (Details)

Goodwill - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Goodwill [Line Items]
Goodwill	$ 1,478	$ 2,103	$ 2,764
Impairment loss	$ 624	$ 657

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2020	Oct. 01, 2019
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Cost	$ 3,156	$ 3,156
Accumulated amortization	(598)	(933)
Finite-lived intangible assets, net	2,558	2,223
Cost	335	333
Indefinite-lived intangible assets, net	333	333
Intangible assets, net	2,891	2,556	$ 2,889
Impairment of indefinite-lived intangible assets	(2)
Indefinite-lived Intangible Assets (Excluding Goodwill), Accumulated Impairment Loss	(2)	0
Acquired technology and patents
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Cost	960	961
Accumulated amortization	(308)	(482)
Finite-lived intangible assets, net	652	479
Cost	2	0
Indefinite-lived intangible assets, net	0	0
Intangible assets, net	652	479
Indefinite-lived Intangible Assets (Excluding Goodwill), Accumulated Impairment Loss	(2)	0
Customer relationships and other intangibles
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Cost	2,154	2,153
Accumulated amortization	(279)	(433)
Finite-lived intangible assets, net	1,875	1,720
Cost	0	0
Indefinite-lived intangible assets, net	0	0
Intangible assets, net	1,875	1,720
Indefinite-lived Intangible Assets (Excluding Goodwill), Accumulated Impairment Loss	0	0
Trademarks and Trade Names Member
Finite-lived and Indefinite-lived Intangible Assets [Line Items]
Cost	42	42
Accumulated amortization	(11)	(18)
Finite-lived intangible assets, net	31	24
Cost	333	333
Indefinite-lived intangible assets, net	333	333
Intangible assets, net	364	357
Indefinite-lived Intangible Assets (Excluding Goodwill), Accumulated Impairment Loss	$ 0	$ 0

Intangible Assets - Narrative (

Intangible Assets - Narrative (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill), Accumulated Impairment Loss			$ 0	$ 2
Amortization of intangible assets	$ 13	$ 262	335	336
Cost			$ 333	335
Impairment charges				$ 2
Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life			1 year
Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life			19 years

Intangible Assets - Amortizatio

Intangible Assets - Amortization Expense Maturity (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Intangible Assets, Net (Excluding Goodwill) [Abstract]
2019	$ 331
2020	304
2021	287
2022	185
2023 and thereafter	1,116
Finite-lived intangible assets, net	$ 2,223	$ 2,558

Supplementary Financial Infor_3

Supplementary Financial Information - Consolidated Statements of Operations Information (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
DEPRECIATION AND AMORTIZATION
Amortization of intangible assets (included in Costs and Operating expenses)	$ 13	$ 262	$ 335	$ 336
Depreciation and amortization of property, plant and equipment and internal use software (included in Costs and Operating expenses)	18	122	88	107
Total depreciation and amortization	31	384	423	443
OTHER INCOME (EXPENSE), NET
Interest income	2	5	6	14
Foreign currency (losses) gains, net	0	28	(16)	(8)
Marketable Securities, Gain (Loss)	0	0	49	0
Income From Transition Services Agreement, Net	3	5	0	0
Other pension and post-retirement benefit credits (costs), net	(8)	13	22	7
Change in fair value of emergence date warrants	0	(17)	(3)	29
Sublease Income	0	0	5	0
Other, net	1	1	0	(1)
Total other income (expense), net	$ (2)	$ 35	63	$ 41
Strategic Partnership Transactions, Realized Gain (Loss)			$ 59

Supplementary Financial Infor_4

Supplementary Financial Information - Reorganization Items (Details) - USD ($) $ in Millions	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Supplementary Financial Information [Line Items]
Net gain on settlement of Liabilities subject to compromise	$ 1,778	$ 1,778	$ 0	$ 0	$ 0
Net gain on fresh start adjustments		1,697	0	0	0
Bankruptcy-related professional fees		(56)	0	0	0
Other items, net		(3)	0	0	0
Reorganization items, net		3,416	0	0	0
Cash payments for reorganization items		2,524	$ 1	$ 0	$ 0
Claims paid		2,468
Payments for emergence and success fees		$ 56

Supplementary Financial Infor_5

Supplementary Financial Information - Consolidated Balance Sheet Information Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Allowance for Doubtful Accounts Receivable:
VALUATION AND QUALIFYING ACCOUNTS
Balance at beginning of year	$ 13	$ 0	$ 4	$ 2
Increase in expense	1	2	5	2
Reductions	(1)	0	(2)	0
Impact of fresh start accounting	(13)	0	0	0
Balance at end of year	0	2	7	4
Deferred Tax Asset Valuation Allowance:
VALUATION AND QUALIFYING ACCOUNTS
Balance at beginning of year	2,152	836	928	919
Increase in expense	452	105	58	43
Impact of fresh start accounting	(471)	0	0	0
Additions (reductions)	(393)	(22)	67	(34)
Balance at end of year	$ 836	$ 919	$ 1,053	$ 928

Supplementary Financial Infor_6

Supplementary Financial Information - Consolidated Balance Sheet Information Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
PROPERTY, PLANT AND EQUIPMENT, NET
Property, plant and equipment	$ 580	$ 506
Less: Accumulated depreciation and amortization	(312)	(251)
Property, plant and equipment, net	268	255
Capital leased assets, accumulated depreciation	(15)	(12)
Leasehold improvements
PROPERTY, PLANT AND EQUIPMENT, NET
Property, plant and equipment	97	101
Machinery and equipment
PROPERTY, PLANT AND EQUIPMENT, NET
Property, plant and equipment	265	221
Capital leased assets	27	17
Assets under construction
PROPERTY, PLANT AND EQUIPMENT, NET
Property, plant and equipment	30	30
Internal use software
PROPERTY, PLANT AND EQUIPMENT, NET
Property, plant and equipment	$ 188	$ 154

Supplementary Financial Infor_7

Supplementary Financial Information - Supplementary Cash Flow Information (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Dec. 16, 2017	Oct. 01, 2017
Other Significant Noncash Transactions [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 366	$ 700	$ 727	$ 752
Restricted Cash, Current	65	0	0	0
OTHER PAYMENTS
Interest payments	15	149	197	206
Income tax payments	7	22	101	56
NON-CASH INVESTING ACTIVITIES
(Decrease) increase in Accounts payable, Other current liabilities and Other liabilities for Capital expenditures	0	1	(4)	6
Restricted Cash, Noncurrent	4	4	4	4
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	435	704	731	756	$ 435	$ 966
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	0	0	10	0
Acquisition of Equipment Under Finance Leases	$ 0	$ 2	9	$ 3
Operating Lease, Payments			66
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			$ 35

Business Restructuring Reserv_3

Business Restructuring Reserves and Programs (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	$ 14	$ 81	$ 30	$ 22
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginning balance	55	65	64	92
Restructuring charges, net	14	81	30	22
Cash payments	(7)	(40)	(26)	(43)
Adjustments	4	0	(2)	(1)
Restructuring Reserve, ending balance	65	92	49	64
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	0	(3)	5	(4)
Prior Period Reclassification Adjustment			5
Fiscal 2018 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	12	70	0	0
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginning balance	0	9	31	54
Restructuring charges, net	12	70	0	0
Cash payments	(3)	(23)	(11)	(19)
Adjustments	0	0	(1)	(2)
Restructuring Reserve, ending balance	9	54	21	31
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	0	(2)	2	(2)
Fiscal 2018 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	0	0	0	20
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginning balance	0	0	11	0
Restructuring charges, net	0	0	0	20
Cash payments	0	0	(5)	(8)
Adjustments	0	0	0	0
Restructuring Reserve, ending balance	0	0	7	11
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	0	0	1	(1)
Fiscal 2020 Restructuring Program Member
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	0	0	8	0
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginning balance	0	0	0	0
Restructuring charges, net	0	0	8	0
Cash payments	0	0	(1)	0
Adjustments	0	0	0	0
Restructuring Reserve, ending balance	0	0	8	0
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	0	0	1	0
Fiscal 2008-2017 Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	1	0	0	0
Restructuring Reserve [Roll Forward]
Restructuring Reserve, beginning balance	55	56	22	38
Restructuring charges, net	1	0	0	0
Cash payments	(4)	(17)	(9)	(16)
Adjustments	4	0	(1)	1
Restructuring Reserve, ending balance	56	38	13	22
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	0	(1)	1	(1)
All Programs
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	13	70	8	20
Restructuring Reserve [Roll Forward]
Restructuring charges, net	13	70	8	20
Employee Separation Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	13	70	6	19
Restructuring Reserve [Roll Forward]
Restructuring charges, net	$ 13	$ 70	$ 6	$ 19

Financing Arrangements - Schedu

Financing Arrangements - Schedule of Debt (Details) - USD ($)	Sep. 30, 2020	Sep. 25, 2020	Sep. 30, 2019	Jun. 11, 2018	Dec. 15, 2017
Debt Instrument [Line Items]
Debt face amount	$ 2,993,000,000		$ 3,224,000,000		$ 2,925,000,000
Debt, Long-term and Short-term, Combined Amount	2,886,000,000		3,119,000,000
Current portion of Long-term debt	0		(29,000,000)
Long-term Debt, Excluding Current Maturities	2,886,000,000		3,090,000,000
Term Loan
Debt Instrument [Line Items]
Debt face amount	1,643,000,000		2,874,000,000
Debt, Long-term and Short-term, Combined Amount	1,611,000,000		2,846,000,000
Senior Notes
Debt Instrument [Line Items]
Debt face amount	1,000,000,000	$ 1,000,000,000	0
Debt, Long-term and Short-term, Combined Amount	984,000,000		0
Convertible Debt [Member]
Debt Instrument [Line Items]
Debt face amount	350,000,000		350,000,000	$ 350,000,000
Debt, Long-term and Short-term, Combined Amount	291,000,000		273,000,000
Unamortized debt discount	(55,000,000)		(72,000,000)
Unamortized Debt Issuance Expense	$ 4,000,000		$ 5,000,000

Financing Arrangements - Term L

Financing Arrangements - Term Loan and ABL (Details)	Sep. 25, 2020USD ($)	Jun. 18, 2018	Dec. 15, 2017USD ($)	Dec. 15, 2017USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Jun. 11, 2018USD ($)
Debt Instrument [Line Items]
Interest Expense				$ 14,000,000		$ 169,000,000	$ 226,000,000	$ 237,000,000
Debt face amount			$ 2,925,000,000	2,925,000,000	$ 2,993,000,000		2,993,000,000	3,224,000,000
Amortization of debt issuance costs and discounts				0		8,000,000	23,000,000	22,000,000
Line of Credit Facility, Remaining Borrowing Capacity					$ 153,000,000		153,000,000
Letters of credit, maximum amount			150,000,000	150,000,000
Line of Credit Facility, Average Outstanding Amount							$ 41,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Minimum fixed charge coverage ratio					1		1
Line of Credit Facility, Current Borrowing Capacity	$ 200,000,000		$ 300,000,000	$ 300,000,000
Term Loan Credit Agreement due December 15, 2024
Debt Instrument [Line Items]
Interest Expense						154,000,000	$ 161,000,000	200,000,000
Debt face amount	$ 800,000,000
Repayments of Debt					$ 981,000,000		1,231,000,000
Convertible Debt [Member]
Debt Instrument [Line Items]
Interest Expense						7,000,000	26,000,000	25,000,000
Debt face amount					350,000,000		350,000,000	350,000,000	$ 350,000,000
Amortization of debt issuance costs and discounts						$ 4,000,000	18,000,000	17,000,000
Debt Issuance Costs, Net									$ 10,000,000
Interest rate, stated percentage									2.25%
Term Loan
Debt Instrument [Line Items]
Debt face amount					1,643,000,000		1,643,000,000	$ 2,874,000,000
Other Assets [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Debt Issuance Costs, Net					2,000,000		2,000,000
Long-term Debt [Member] | Term Loan Credit Agreement due December 15, 2024
Debt Instrument [Line Items]
Debt Issuance Costs, Net					32,000,000		32,000,000
ABL Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Minimum net borrowing availability					$ 16,000,000		$ 16,000,000
Debt Instrument, Covenant Terms, Percent Of Total Borrowing Base					10.00%		10.00%
ABL Credit Agreement | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest Expense							$ 1,000,000
Base Rate Loans [Member] | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate, stated percentage	1.00%		0.75%	0.75%
Step up or step down percentage			0.25%	0.25%
Base Rate Loans [Member] | Line of Credit | Fed Funds Effective Rate Overnight Index Swap Rate [Member] | Revolving Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%		0.50%
LIBOR Loans Denominated In US Dollars [Member] | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate, stated percentage	2.00%		1.75%	1.75%
Step up or step down percentage	0.25%		0.25%	0.25%
Canadian Prime Rate Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Period	30 days		30 days
Canadian Prime Rate Loans [Member] | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate, stated percentage	1.00%		0.75%	0.75%
Step up or step down percentage	0.25%		0.25%	0.25%
CDOR Loans [Member] | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate, stated percentage	2.00%		1.75%	1.75%
Step up or step down percentage	0.25%		0.25%	0.25%
LIBOR Loans Denominated In Sterling [Member] | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate, stated percentage	2.00%		1.75%	1.75%
Step up or step down percentage	0.25%		0.25%	0.25%
EURIBOR Loans Denominated In Euro [Member] | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate, stated percentage	2.00%		1.75%	1.75%
Step up or step down percentage	0.25%		0.25%	0.25%
Overnight LIBOR Loans [Member] | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate, stated percentage	2.00%		1.75%	1.75%
Step up or step down percentage	0.25%		0.25%	0.25%
LIBOR Loans [Member] | Term Loan | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest rate, stated percentage		4.25%	4.75%	4.75%
LIBOR Loans [Member] | Term Loan | Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.00%	1.00%
ABR Loans [Member] | Term Loan
Debt Instrument [Line Items]
Interest rate, stated percentage			3.75%	3.75%
ABR Loans [Member] | Term Loan | Fed Funds Effective Rate Overnight Index Swap Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.50%	0.50%
ABR Loans [Member] | Term Loan | Alternative Base Rate [Member]
Debt Instrument [Line Items]
Interest rate, stated percentage		3.25%
Interest Expense | Term Loan Credit Agreement due December 15, 2024
Debt Instrument [Line Items]
Debt Issuance Costs, Net					$ 9,000,000		9,000,000
Write off of Deferred Debt Issuance Cost							$ 5,000,000

Financing Arrangements - Senior

Financing Arrangements - Senior Notes (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 25, 2020
Debt Instrument [Line Items]
Debt face amount	$ 2,925		$ 2,993	$ 3,224
Interest Expense	$ 14	$ 169	$ 226	237
Senior Notes | Before 9/15/23 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage			100.00%
Senior Notes | After 9/15/23 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage			40.00%
Senior Notes
Debt Instrument [Line Items]
Debt face amount			$ 1,000	$ 0	$ 1,000
Interest rate, stated percentage					6.125%
Interest Expense			$ 1

Financing Arrangements - Conver

Financing Arrangements - Convertible Notes (Details)	Jun. 11, 2018USD ($)$ / shares	Dec. 15, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)
Debt Instrument [Line Items]
Debt face amount		$ 2,925,000,000		$ 2,993,000,000	$ 3,224,000,000
Interest Expense		$ 14,000,000	$ 169,000,000	$ 226,000,000	237,000,000
Proceeds from Convertible Debt	$ 314,000,000
Debt Instrument, Convertible, Conversion Ratio	36.0295			0.273
Conversion price (in usd per share) | $ / shares	$ 27.76
Long-term Debt, Gross	$ 258,000,000			$ 2,993,000,000
Debt Instrument, Convertible, Carrying Amount of Equity Component	$ 92,000,000
Debt Instrument, Convertible, Terms of Conversion Feature	1,000
Convertible Notes
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Liability [Member]
Debt Instrument [Line Items]
Debt Issuance Costs, Net	$ 7,000,000
Equity [Member]
Debt Instrument [Line Items]
Debt Issuance Costs, Net	$ 3,000,000
Debt Instrument, Redemption, Period One [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Trading Days	20
Debt Instrument, Convertible, Threshold Consecutive Trading Days	30
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger	130.00%
Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Trading Days	5
Debt Instrument, Convertible, Threshold Consecutive Trading Days	5
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger	98.00%
Convertible Debt [Member]
Debt Instrument [Line Items]
Debt face amount	$ 350,000,000			350,000,000	350,000,000
Interest Expense			$ 7,000,000	26,000,000	25,000,000
Interest rate, stated percentage	2.25%
Debt Instrument, Convertible, Carrying Amount of Equity Component				$ 291,000,000	$ 273,000,000
Debt Issuance Costs, Net	$ 10,000,000
Convertible Debt [Member] | Over-Allotment Option [Member]
Debt Instrument [Line Items]
Debt face amount	$ 50,000,000

Financing Arrangements - Bond H

Financing Arrangements - Bond Hedge and Call Spread Warrants (Details) shares in Thousands, $ in Millions	Jun. 11, 2018USD ($)$ / unitshares	Dec. 15, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)
Debt Instrument [Line Items]
Derivative, Bond Hedge | shares	12,600
Derivative, Price Risk Option Strike Price | $ / unit	37.3625
Payments for Hedge, Financing Activities | $	$ 84	$ 0	$ 84	$ 0	$ 0
Warrants issued (in shares) | shares	12,600
Proceeds from Hedge, Financing Activities | $	$ 58
Convertible Debt [Member]
Debt Instrument [Line Items]
Derivative, Price Risk Option Strike Price | $ / unit	27.76

Financing Arrangements - Rates

Financing Arrangements - Rates (Details) - USD ($) $ in Millions	2 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt, Weighted Average Interest Rate		6.50%	6.30%
Debt Instrument, Interest Rate, Effective Percentage		9.20%
Interest Expense, Not Recorded Due To Bankruptcy Process	$ 94

Financing Arrangements (Details

Financing Arrangements (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Debt, Long-term and Short-term, Combined Amount	$ 2,886	$ 3,119
Debt Instrument, Interest Rate, Effective Percentage	9.20%
Term Loan
Debt Instrument [Line Items]
Debt, Long-term and Short-term, Combined Amount	$ 1,611	2,846
Senior Notes
Debt Instrument [Line Items]
Debt, Long-term and Short-term, Combined Amount	984	0
Convertible Debt [Member]
Debt Instrument [Line Items]
Debt, Long-term and Short-term, Combined Amount	$ 291	$ 273

Financing Arrangements - Maturi

Financing Arrangements - Maturities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 11, 2018
Debt Disclosure [Abstract]
Long-Term Debt, Maturity, Year One	$ 0
Long-Term Debt, Maturity, Year Two	0
Long-Term Debt, Maturity, Year Three	350
Long-Term Debt, Maturity, Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five And Thereafter	2,643
Long-term Debt, Gross	$ 2,993	$ 258

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Narrative (Details)	Jul. 01, 2020counterparty	May 16, 2018counterparty	Sep. 30, 2020USD ($)	Sep. 23, 2020USD ($)	Sep. 30, 2019USD ($)	Nov. 14, 2018USD ($)	Dec. 15, 2017$ / sharesshares
Derivative [Line Items]
Class of warrant or right, number of securities called by each warrant or right (in shares) | shares							5,645,200
Class of warrant or right, exercise price of warrants or rights (in USD per share) | $ / shares							$ 25.55
Warrant Repurchase Program, Number of Securities Called by Warrants or Rights, Authorized Amount						$ 15,000,000
Derivative Instruments and Hedging Activities			Derivative Instruments and Hedging Activities The Company accounts for derivative financial instruments in accordance with FASB ASC Topic 815 "Derivatives and Hedging," ("ASC 815") and does not enter into derivatives for trading or speculative purposes. Interest Rate Contracts The Company, from time-to-time, enters into interest rate swap contracts as a hedge against changes in interest rates on its outstanding variable rate loans. On May 16, 2018, the Company entered into interest rate swap agreements with six counterparties, which fix a portion of the variable interest due under its Term Loan Credit Agreement (the "Original Swap Agreements"). Under the terms of the Original Swap Agreements, which mature on December 15, 2022, the Company pays a fixed rate of 2.935% and receives a variable rate of interest based on one-month LIBOR. Through September 23, 2020, the total $1,800 million notional amount of the Original Swap Agreements were designated as cash flow hedges and deemed highly effective as defined under ASC 815. On September 23, 2020, the Company entered into an interest rate swap agreement for a notional amount of $257 million (the “Offsetting Swap Agreement”). Under the terms of the Offsetting Swap Agreement, which matures on December 15, 2022, the Company pays a variable rate of interest based on one-month LIBOR and receives a fixed rate of 0.1745%. The Company entered into the Offsetting Swap Agreement to maintain a net notional amount less than the amount of the Company’s variable rate loans outstanding. The Offsetting Swap Agreement was not designated for hedge accounting treatment. On September 23, 2020, Original Swap Agreements with a notional amount of $257 million were also de-designated from hedge accounting treatment. As of September 30, 2020, Original Swap Agreements with a notional amount of $1,543 million continue to be designated as cash flow hedges and deemed highly effective as defined under ASC 815. On July 1, 2020, the Company entered into interest rate swap agreements with four counterparties, which fix a portion of the variable interest due on its Term Loan Credit Agreement (the "New Swap Agreements") from December 15, 2022 (the maturity date of the Original Swap Agreements) through December 15, 2024. Under the terms of the New Swap Agreements, the Company will pay a fixed rate of 0.7047% and receive a variable rate of interest based on one-month LIBOR. The total notional amount of the New Swap Agreements is $1,400 million. Since their execution, the New Swap Agreements have been designated as cash flow hedges and deemed highly effective as defined by ASC 815. The Company records changes in the fair value of interest rate swap agreements designated as cash flow hedges initially within Accumulated other comprehensive loss in the Consolidated Balance Sheets. As interest expense is recognized on the Term Loan Credit Agreement, the corresponding deferred gain or loss on the cash flow hedge is reclassified from Accumulated other comprehensive loss to Interest expense in the Consolidated Statements of Operations. The Company records changes in the fair value of interest rate swap agreements not designated for hedge accounting within Interest expense. On September 23, 2020, the Company froze a $15 million deferred loss within Accumulated other comprehensive loss for the de-designated Original Swap Agreements, which will be reclassified to Interest expense over the term of the Original Swap Agreements. Based on the amount in Accumulated other comprehensive loss at September 30, 2020, approximately $50 million would be reclassified to interest expense in the next twelve months. It is management's intention that the net notional amount of interest rate swap agreements be less than the variable rate loans outstanding during the life of the derivatives. Foreign Currency Forward Contracts The Company, from time to time, utilizes foreign currency forward contracts primarily to hedge fluctuations associated with certain monetary assets and liabilities including receivables, payables and certain intercompany balances. These foreign currency forward contracts are not designated for hedge accounting treatment. As a result, changes in the fair value of these contracts are recorded as a component of Other income (expense), net to offset the change in the value of the hedged assets and liabilities. As of September 30, 2020, the Company maintained open foreign currency forward contracts with a total notional value of $375 million, primarily hedging the British Pound Sterling, Euro, Chinese Renminbi and Indian Rupee. As of September 30, 2019, the Company maintained open foreign currency forward contracts with a total notional value of $400 million, primarily hedging the British Pound Sterling, Indian Rupee, Chinese Renminbi, Czech Koruna, Mexican Peso and Australian Dollar. Emergence Date Warrants In accordance with the Plan of Reorganization, the Company issued warrants to purchase 5,645,200 shares of Company common stock under a warrant agreement to the holders of the Predecessor second lien obligations extinguished pursuant to the Plan of Reorganization (the "Emergence Date Warrants"). Each Emergence Date Warrant has an exercise price of $25.55 per share and expires December 15, 2022. The Emergence Date Warrants contain certain derivative features that require them to be classified as a liability and for changes in the fair value of the liability to be recognized in earnings each reporting period. On November 14, 2018, the Company's Board of Directors approved a warrant repurchase program, authorizing the Company to repurchase up to $15 million worth of the Emergence Date Warrants. None of the Emergence Date Warrants have been exercised or repurchased as of September 30, 2020. The fair value of the Emergence Date Warrants was determined using a probability weighted Black-Scholes option pricing model. This model requires certain input assumptions including risk-free interest rates, volatility, expected life and dividend rates. Selection of these inputs involves significant judgment. The fair value of the Emergence Date Warrants as of September 30, 2020 and 2019 was determined using the input assumptions summarized below: As of September 30, 2020 2019 Expected volatility 68.53 % 56.89 % Risk-free interest rates 0.14 % 1.55 % Contractual remaining life (in years) 2.21 3.21 Price per share of common stock $15.20 $10.23 In determining the fair value of the Emergence Date Warrants, the dividend yield was assumed to be zero as the Company does not anticipate paying dividends throughout the term of the warrants. Financial Statement Information Related to Derivative Instruments The following table summarizes the fair value of the Company's derivatives on a gross basis, including accrued interest, segregated between those that are designated as hedging instruments and those that are not designated as hedging instruments: September 30, 2020 September 30, 2019 (In millions) Balance Sheet Caption Asset Liability Asset Liability Derivatives Designated as Hedging Instruments: Interest rate contracts Other current liabilities — 43 — 23 Interest rate contracts Other liabilities — 58 — 58 — 101 — 81 Derivatives Not Designated as Hedging Instruments: Interest rate contracts Other current liabilities — 7 — — Interest rate contracts Other liabilities — 9 — — Foreign exchange contracts Other current assets 1 — 1 — Foreign exchange contracts Other current liabilities — 2 — — Emergence Date Warrants Other liabilities — 8 — 5 1 26 1 5 Total derivative fair value $ 1 $ 127 $ 1 $ 86 The following table provides information regarding the location and amount of pre-tax (losses) gains for interest rate swaps designated as cash flow hedges: Fiscal years ended September 30, Period from December 16, 2017 2020 2019 (In millions) Interest Expense Other Comprehensive (Loss) Income Interest Expense Other Comprehensive (Loss) Income Interest Expense Other Comprehensive (Loss) Income Financial Statement Line Item in which Cash Flow Hedges are Recorded $ (226) $ (72) $ (237) $ (191) $ (169) $ 18 Impact of cash flow hedging relationships: Loss recognized in AOCI - on interest rate swaps — (69) — (87) — (9) Interest expense reclassified from AOCI (35) 35 (10) 10 (6) 6 The following table provides information regarding the pre-tax (losses) gains for derivatives not designated as hedging instruments on the Consolidated Statements of Operations: Fiscal years ended September 30, Period from December 16, 2017 (In millions) Location of Derivative Pre-tax Gain (Loss) 2020 2019 Emergence Date Warrants Other income (expense), net (3) $ 29 $ (17) Foreign exchange contracts Other income (expense), net (1) (5) — The Company records its derivatives on a gross basis in the Consolidated Balance Sheets. The Company has master netting agreements with several of its financial institution counterparties. The following table provides information on the Company's derivative positions as if those subject to master netting arrangements were presented on a net basis, allowing for the right to offset by counterparty per the master netting agreements: September 30, 2020 September 30, 2019 (In millions) Asset Liability Asset Liability Gross amounts recognized in the Consolidated Balance Sheet $ 1 $ 127 $ 1 $ 86 Gross amount subject to offset in master netting arrangements not offset in the Consolidated Balance Sheet (1) (1) (1) (1) Net amounts $ — $ 126 $ — $ 85
Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount			$ 375,000,000		$ 400,000,000
Original Interest Rate Swap [Member]
Derivative [Line Items]
Number of counterparties | counterparty		6
Derivative fixed interest rate		2.935%
Derivative, Notional Amount			1,543,000,000
Deferred Loss, Frozen, To Be Reclassified to Interest Expense				$ 15,000,000
Original Interest Rate Swap [Member] | Derivatives Designated as Hedging Instruments:
Derivative [Line Items]
Derivative, Notional Amount				1,800,000,000
Original Interest Rate Swap [Member] | Derivatives Not Designated as Hedging Instruments:
Derivative [Line Items]
Derivative, Notional Amount				$ 257,000,000
Offsetting Swap Agreement [Member]
Derivative [Line Items]
Derivative fixed interest rate				0.1745%
Derivative, Notional Amount				$ 257,000,000
New Interest Rate Swap [Member]
Derivative [Line Items]
Number of counterparties | counterparty	4
Derivative fixed interest rate	0.7047%
Derivative, Notional Amount			1,400,000,000
Expected gain (loss) to be reclassified within twelve months			$ 50,000,000

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Assumptions Used (Details)	Sep. 30, 2020year$ / shares	Sep. 30, 2019year$ / shares
Expected volatility
Derivative [Line Items]
Warrants, measurement input	0.6853	0.5689
Risk-free interest rates
Derivative [Line Items]
Warrants, measurement input	0.0014	0.0155
Contractual remaining life (in years)
Derivative [Line Items]
Warrants, measurement input | year	2.21	3.21
Warrants
Derivative [Line Items]
Price per share of common stock (in usd per share) | $ / shares	$ 15.20	$ 10.23

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Derivative Asset	$ 1	$ 1
Gross amounts recognized in the consolidated balance sheet, Liability	127	86
Derivatives Designated as Hedging Instruments:
Derivative [Line Items]
Derivative Asset	0	0
Gross amounts recognized in the consolidated balance sheet, Liability	101	81
Derivatives Designated as Hedging Instruments: | Other current liabilities | Interest rate contracts
Derivative [Line Items]
Derivative Asset	0	0
Gross amounts recognized in the consolidated balance sheet, Liability	43	23
Derivatives Designated as Hedging Instruments: | Other liabilities | Interest rate contracts
Derivative [Line Items]
Derivative Asset	0	0
Gross amounts recognized in the consolidated balance sheet, Liability	58	58
Derivatives Not Designated as Hedging Instruments:
Derivative [Line Items]
Derivative Asset	1	1
Gross amounts recognized in the consolidated balance sheet, Liability	26	5
Derivatives Not Designated as Hedging Instruments: | Other current liabilities | Interest rate contracts
Derivative [Line Items]
Derivative Asset	0	0
Gross amounts recognized in the consolidated balance sheet, Liability	7	0
Derivatives Not Designated as Hedging Instruments: | Other liabilities | Interest rate contracts
Derivative [Line Items]
Derivative Asset	0	0
Gross amounts recognized in the consolidated balance sheet, Liability	9	0
Derivatives Not Designated as Hedging Instruments: | Other liabilities | Warrants
Derivative [Line Items]
Derivative Asset	0	0
Gross amounts recognized in the consolidated balance sheet, Liability	8	5
Derivatives Not Designated as Hedging Instruments: | Other current assets | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative Asset	1	1
Gross amounts recognized in the consolidated balance sheet, Liability	0	0
Derivatives Not Designated as Hedging Instruments: | Other current liabilities | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative Asset	0	0
Gross amounts recognized in the consolidated balance sheet, Liability	$ 2	$ 0

Derivative Instruments and He_6

Derivative Instruments and Hedging Activities - Derivatives Designated as Cash Flow Hedges (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2017
Derivative [Line Items]
Interest Expense	$ 14	$ 169	$ 226	$ 237
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	658	18	(72)	(191)	$ 658
Accumulated Other Comprehensive (Loss) Income
Derivative [Line Items]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 658	18	(72)	(191)
Interest Expense | Derivatives Designated as Hedging Instruments:
Derivative [Line Items]
Loss recognized in AOCI - on interest rate swaps		0	0	0
Interest expense reclassified from AOCI		(6)	(35)	(10)
Other Comprehensive (Loss) Income | Derivatives Designated as Hedging Instruments:
Derivative [Line Items]
Loss recognized in AOCI - on interest rate swaps		(9)	(69)	(87)
Interest expense reclassified from AOCI		$ 6	$ 35	$ 10

Derivative Instruments and He_7

Derivative Instruments and Hedging Activities - Derivatives Not Designated as Hedging Instruments (Details) - Other income (expense), net - Derivatives Not Designated as Hedging Instruments: - USD ($) $ in Millions	10 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Emergence Date Warrants
Derivative [Line Items]
Derivative, gain (loss)	$ (17)	$ (3)	$ 29
Foreign currency forward contracts
Derivative [Line Items]
Derivative, gain (loss)	$ 0	$ (1)	$ (5)

Derivative Instruments and He_8

Derivative Instruments and Hedging Activities - Presented on a Net Basis (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Gross amounts recognized in the consolidated balance sheet, Asset	$ 1	$ 1
Gross amounts recognized in the consolidated balance sheet, Liability	127	86
Gross amount subject to offset in master netting arrangements not offset in the Consolidated Balance Sheet, Asset	(1)	(1)
Gross amount subject to offset in master netting arrangements not offset in the Consolidated Balance Sheet, Liability	(1)	(1)
Derivative Asset	0	0
Derivative Liability	$ 126	$ 85

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019	Mar. 09, 2018
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 1	$ 11
Liabilities	127	91
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1	1
Liabilities	119	81
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	10
Liabilities	8	10
Corporate Debt Securities [Member] | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	10
Corporate Debt Securities [Member] | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Corporate Debt Securities [Member] | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Corporate Debt Securities [Member] | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	10
Interest rate contracts | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	117	81
Interest rate contracts | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Interest rate contracts | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	117	81
Interest rate contracts | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Foreign currency forward contracts | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1	1
Liabilities	2	0
Foreign currency forward contracts | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Foreign currency forward contracts | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1	1
Liabilities	2	0
Foreign currency forward contracts | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Emergence Date Warrants | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	8	5
Emergence Date Warrants | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Emergence Date Warrants | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Emergence Date Warrants | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	8	5
Spoken [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration			$ 14
Spoken [Member] | Spoken acquisition Earn-outs | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	5
Spoken [Member] | Spoken acquisition Earn-outs | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Spoken [Member] | Spoken acquisition Earn-outs | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Spoken [Member] | Spoken acquisition Earn-outs | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	$ 0	$ 5

Fair Value Measurements - Level

Fair Value Measurements - Level 3 Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	$ 0	$ 0	$ (10)	$ 0
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of derivative liability, beginning balance			(10)
Fair value of derivative liability, ending balance			0	(10)
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net			(10)
Fair Value, Option, Changes in Fair Value, Gain (Loss)			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements			0
Level 3 | Warrant [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of derivative liability, beginning balance			(5)
Fair value of derivative liability, ending balance			(8)	(5)
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net			0
Fair Value, Option, Changes in Fair Value, Gain (Loss)			3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements			0
Level 3 | Spoken acquisition Earn-outs | Spoken [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of derivative liability, beginning balance			(5)
Fair value of derivative liability, ending balance			0	$ (5)
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net			0
Fair Value, Option, Changes in Fair Value, Gain (Loss)			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements			$ 5

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Financial Instruments (Details) - USD ($)	Sep. 30, 2020	Sep. 25, 2020	Sep. 30, 2019	Jun. 11, 2018	Dec. 15, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 2,977,000,000		$ 3,037,000,000
Debt face amount	2,993,000,000		3,224,000,000		$ 2,925,000,000
Term Loan Credit Agreement due December 15, 2024 and 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	1,624,000,000		2,739,000,000
Debt face amount	1,643,000,000		2,874,000,000
Convertible 2.25% Senior Notes due June 15, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate, stated percentage				2.25%
Long-term debt, fair value	331,000,000		298,000,000
Debt face amount	350,000,000		350,000,000	$ 350,000,000
Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate, stated percentage		6.125%
Long-term debt, fair value	1,022,000,000		0
Debt face amount	$ 1,000,000,000	$ 1,000,000,000	$ 0

Income Taxes - Income Taxes Nar

Income Taxes - Income Taxes Narrative (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Tax Examination [Line Items]
Net operating loss recognition and intellectual property	$ 0		$ (366)	$ 0	$ 0
Federal tax rate		35.00%		21.00%		24.50%
Goodwill impairment				$ 624	657
Tax-effected net operating losses				1,006
Change in valuation allowance, deferred tax asset	(1,316)		82	125	9
Valuation allowance				1,053	928
U.S. Federal, state and local NOL's				17
Foreign NOL's				989
Unrecognized tax benefits	272		174	140	147	$ 174	$ 268
Unrecognized tax benefits, penalties and interest accrual				25
Unrecognized tax benefits that would impact the effective tax rate				89
Interest expense (benefit)	1		0	(3)	(4)
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Liability, Income Tax Benefit			$ 245
Deferred Tax Liabilities, Undistributed Foreign Earnings				17
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Foreign Subsidiaries				20
Undistributed Foreign Earnings, Outside Basis Difference				83
Products & Solutions
Income Tax Examination [Line Items]
Goodwill impairment				624	$ 657
Domestic Tax Authority
Income Tax Examination [Line Items]
Valuation allowance				$ 76
Operating loss carryforwards, expiration terms in excess of				10 years
German Tax Authority
Income Tax Examination [Line Items]
Valuation allowance				$ 341
Foreign NOL's				260
Luxembourg Tax Authority
Income Tax Examination [Line Items]
Valuation allowance				589
Foreign NOL's				679
All other international
Income Tax Examination [Line Items]
Valuation allowance				47
Net Operating Loss And Tax Carryforwards And Other
Income Tax Examination [Line Items]
Change in valuation allowance	787
Deferred Tax Asset For Non-US Jurisdictions
Income Tax Examination [Line Items]
Change in valuation allowance	47
Fresh Start Accounting Adjustments
Income Tax Examination [Line Items]
Change in valuation allowance	$ 460
Prior Period Examinations
Income Tax Examination [Line Items]
Decrease in unrecognized tax benefits over the next twelve months				8
Expiration Of Statute Of Limitations
Income Tax Examination [Line Items]
Decrease in unrecognized tax benefits over the next twelve months				$ 5

Income Taxes - Income Taxes by

Income Taxes - Income Taxes by Location (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
LOSS BEFORE INCOME TAXES:
U.S.	$ 3,353									$ (165)	$ (639)	$ (510)
Foreign	83									(94)	21	(159)
(LOSS) INCOME BEFORE INCOME TAXES	3,436									(259)	(618)	(669)
CURRENT
Federal	0									0	(58)	(20)
State and local	0									4	(10)	(7)
Foreign	(4)									(40)	(23)	(29)
Current income tax provision (benefit)	(4)									(36)	(91)	(56)
DEFERRED
Federal	(453)									530	30	47
State and local	(19)									34	3	10
Foreign	17									18	(4)	(3)
Deferred income tax provision (benefit)	(455)									582	29	54
(Provision for) benefit from income taxes	$ (459)	$ 20	$ (20)	$ (37)	$ (25)	$ (32)	$ 27	$ 6	$ (3)	$ 546	$ (62)	$ (2)

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Taxes (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
DEFERRED INCOME TAX ASSETS:
Benefit obligations	$ 218	$ 225
Net operating losses / credit carryforwards	981	918
Property, plant and equipment	8	15
Other	13	0
Valuation allowance	(1,053)	(928)
Deferred income tax assets	167	230
DEFERRED INCOME TAX LIABILITIES:
Goodwill and intangible assets	(174)	(213)
Other/accrued liabilities	0	(54)
Deferred income tax liabilities	(174)	(267)
Net deferred income tax liabilities	$ (7)	$ (37)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Taxes at U.S. Federal Statutory Rate (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income tax benefit (provision) computed at the U.S. Federal statutory rate	$ (1,203)									$ 64	$ 130	$ 140
State and local income taxes, net of federal income tax effect	10									(12)	2	11
Tax differentials on foreign earnings	182									(12)	0	(11)
Loss on foreign subsidiaries	0									43	28	29
Taxes on unremitted foreign earnings and profits	7									4	8	4
Non-deductible portion of goodwill	0									0	(125)	(123)
Non-deductible reorganization items	(11)									0	0	0
Adjustment to deferred taxes	(1)									4	(14)	16
Audit settlements	(6)									(48)	6	5
Credits and other taxes	(1)									(5)	(2)	4
Impact of Tax Cuts and Jobs Act	0									245	(3)	1
NOL recognition / intellectual property	0									366	0	0
Warrants	0									(4)	(1)	6
Debt refinancing	0									(8)	0	0
Non-deductible impact of fresh start accounting	(555)									0	0	0
Non-taxable cancellation of debt income	313									0	0	0
Attribute reduction	(452)									0	0	0
Rate changes	0									(3)	(3)	(19)
U.S. tax on foreign source income	(2)									(10)	0	0
Valuation allowance	1,199									(85)	(58)	(43)
Other differences—net	61									7	(14)	(14)
(Provision for) benefit from income taxes	$ (459)	$ 20	$ (20)	$ (37)	$ (25)	$ (32)	$ 27	$ 6	$ (3)	$ 546	$ (62)	$ (2)

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued			$ 25
Reconciliation of Gross Unrecognized Tax Benefits [Roll Forward]
Gross UTB balance beginning	$ 268	$ 272	147	$ 174
Additions based on tax positions relating to the period	4	57	4	10
Change to tax positions relating to prior periods		(143)	(1)	(32)
Tax Adjustments, Settlements, and Unusual Provisions			(2)
Statute of limitations expirations		(12)	(8)	(5)
Gross UTB balance ending	$ 272	$ 174	140	$ 147
Unrecognized Tax Benefits that Would Impact Effective Tax Rate			$ 89

Benefit Obligations - Narrative

Benefit Obligations - Narrative (Details) - USD ($)	Sep. 30, 2020	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Benefits settlement			$ 340,000,000	$ 0		$ 0	$ 0
Reorganization, stock issued for employee benefit plans		$ 92,000,000	92,000,000
Debtor reorganization items, gain (loss) on settlement of liabilities subject to compromise, pension plan for salaried employees			(516,000,000)
Net gain on settlement of Liabilities subject to compromise		1,778,000,000	1,778,000,000	0		0	0
Payment for pension trust			49,000,000	0		0	0
Defined Benefit Plan, Reimbursement of Prior Period Payments						3,000,000	3,000,000
Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of actuarial loss					$ 3,000,000
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Debtor reorganization items, gain (loss) on settlement of liabilities subject to compromise, pension plan for salaried employees			(516,000,000)
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Plan obligations, increase (decrease) for plan amendment							(7,000,000)
Contributions by employer			2,000,000	7,000,000		10,000,000	12,000,000
Expected future benefit payments, next 12 months	$ 17,000,000					17,000,000
Discount rate in next fiscal year	2.69%
Benefit obligation, period increase (decrease)						25,000,000
Saving Plans
Defined Benefit Plan Disclosure [Line Items]
Savings plan benefit cost			$ 0	7,000,000		$ 8,000,000	$ 8,000,000
Avaya Inc. Pension Plan for Salaried Employees | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Benefits settlement		$ 340,000,000
Reorganization, stock issued for employee benefit plans (in shares)		6,100,000	6,100,000
Reorganization, stock issued for employee benefit plans		$ 92,000,000	$ 92,000,000
Plan obligations, increase (decrease) for plan amendment		(2,192,000,000)
Plan assets, increase (decrease) for plan amendment		(1,573,000,000)
ASPP Plan
Defined Benefit Plan Disclosure [Line Items]
Plan obligations, increase (decrease) for plan amendment		(88,000,000)
Settlement consideration		17,000,000
Net gain on settlement of Liabilities subject to compromise			53,000,000
Fresh-start adjustment, increase (decrease), pension obligations		3,000,000	3,000,000
Accumulated Defined Benefit Plans Adjustment Attributable to Parent | Avaya Inc. Pension Plan for Salaried Employees | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Settlement gain (loss), before tax		(703,000,000)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent | ASPP Plan
Defined Benefit Plan Disclosure [Line Items]
Settlement gain (loss), before tax		(18,000,000)
U.S. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%					100.00%	100.00%
Contributions by employer						$ 10,000,000	$ 27,000,000
Expected future benefit payments, next 12 months	$ 74,000,000					74,000,000
Actuarial loss (gain)						55,000,000	131,000,000
Estimated future employer contributions in next fiscal year	$ 18,000,000					18,000,000
Net periodic benefit cost (credit)			5,000,000	(20,000,000)		(22,000,000)	(17,000,000)
Amortization of actuarial loss			$ (20,000,000)	$ 0		$ 0	$ 0
Discount rate in next fiscal year	2.50%		3.19%	3.29%		2.84%	3.94%
Benefit obligation, period increase (decrease)						$ 66,000,000
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Change Due to Subsequent Interim Measurement, Weighted-Average Expected Long-term Rate of Return on Plan Assets						(59.00%)
U.S. | Pension Plan | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of actuarial loss					2,000,000
U.S. | Pension Plan | Change in Assumptions for Plans
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss (gain)						$ 10,000,000
U.S. | Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%					100.00%	100.00%
Plan obligations, increase (decrease) for plan amendment						$ 0	$ (7,000,000)
Contributions by employer						10,000,000	12,000,000
Actuarial loss (gain)						30,000,000	44,000,000
Net periodic benefit cost (credit)			$ 0	$ 4,000,000		1,000,000	5,000,000
Amortization of actuarial loss			$ (2,000,000)	$ 0		$ 0	$ 1,000,000
Discount rate in next fiscal year			3.37%	3.39%		2.18%	4.02%
Amortization of prior service cost			$ (3,000,000)	$ 0		$ (1,000,000)	$ 0
U.S. | Post-retirement Benefits | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of actuarial loss					2,000,000
Amortization of prior service cost					$ 1,000,000
U.S. | Post-retirement Benefits | Change in Assumptions for Plans
Defined Benefit Plan Disclosure [Line Items]
Actuarial loss (gain)						5,000,000
U.S. | Postretirement Health Coverage
Defined Benefit Plan Disclosure [Line Items]
Expected future benefit payments, next 12 months	$ 11,000,000					11,000,000
Non-US
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer			3,000,000	22,000,000		$ 22,000,000	$ 23,000,000
Non-US | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%					100.00%	100.00%
Contributions by employer						$ 22,000,000	$ 23,000,000
Expected future benefit payments, next 12 months	$ 24,000,000					24,000,000
Actuarial loss (gain)						(34,000,000)	76,000,000
Estimated future employer contributions in next fiscal year	$ 24,000,000					24,000,000
Net periodic benefit cost (credit)			6,000,000	12,000,000		11,000,000	15,000,000
Amortization of actuarial loss			$ (2,000,000)	$ 0		$ 0	$ 0
Discount rate in next fiscal year	0.86%		1.22%	1.92%		0.87%	1.92%
Benefit obligation, period increase (decrease)						$ 2,000,000
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Change Due to Subsequent Interim Measurement, Weighted-Average Expected Long-term Rate of Return on Plan Assets						(1.00%)
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Change Due to Subsequent Interim Measurement, Weighted-Average Expected Long-term Rate of Return on Plan Assets						(48.00%)
Not Pre-Funded | U.S.
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer			$ 49,000,000	$ 43,000,000		$ 10,000,000	$ 27,000,000
Discharge of Debt
Defined Benefit Plan Disclosure [Line Items]
Benefits settlement		340,000,000
Net gain on settlement of Liabilities subject to compromise			1,778,000,000
Fresh-start adjustment, increase (decrease), pension obligations		246,000,000	$ 246,000,000
Payment for pension trust		$ 49,000,000
Long duration fixed income
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	66.00%					66.00%

Benefit Obligations - Change in

Benefit Obligations - Change in Benefit Obligation and Fair Value (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Post-retirement Benefits
Change in benefit obligation
Plan obligations, increase (decrease) for plan amendment				$ (7)
Change in plan assets
Employer contributions	$ 2	$ 7	$ 10	12
Weighted average assumptions used to determine benefit obligations
Discount rate	3.77%
U.S. | Pension Plan
Change in benefit obligation
Benefit obligation as of beginning of year			1,134	1,050
Service cost	$ 1	3	4	3
Interest cost	$ 22	28	29	40
Actuarial loss (gain)			55	131
Benefits paid			(77)	(90)
Benefit obligation as of end of year		1,050	1,145	1,134
Change in plan assets
Fair value of plan assets as of beginning of year			915	881
Actual return on plan assets			79	97
Employer contributions			10	27
Benefits paid			(77)	(90)
Fair value of plan assets as of end of period		881	927	915
Underfunded status at end of period			(218)	(219)
Amount recognized in the Consolidated Balance Sheets consists of:
Accrued benefit liability, noncurrent			(218)	(219)
Net amount recognized			(218)	(219)
Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of:
Net prior service cost (credit)			110	79
Net amount recognized			$ 110	$ 79
Weighted average assumptions used to determine benefit obligations
Discount rate	3.70%		2.50%	3.09%
Rate of compensation increase			3.00%	3.00%
U.S. | Post-retirement Benefits
Change in benefit obligation
Benefit obligation as of beginning of year			$ 404	$ 368
Service cost	$ 0	1	1	1
Interest cost	3	11	11	14
Actuarial loss (gain)			30	44
Benefits paid			(15)	(16)
Plan obligations, increase (decrease) for plan amendment			0	(7)
Benefit obligation as of end of year		368	431	404
Change in plan assets
Fair value of plan assets as of beginning of year			191	178
Actual return on plan assets			20	17
Employer contributions			10	12
Benefits paid			(15)	(16)
Fair value of plan assets as of end of period		178	206	191
Underfunded status at end of period			(225)	(213)
Amount recognized in the Consolidated Balance Sheets consists of:
Liability, Defined Benefit Plan, Current			(10)	(13)
Accrued benefit liability, noncurrent			(215)	(200)
Net amount recognized			(225)	(213)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax			(6)	(7)
Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of:
Net actuarial loss (gain)			23	3
Net amount recognized			$ 17	$ (4)
Weighted average assumptions used to determine benefit obligations
Discount rate			2.69%	3.17%
Rate of compensation increase			3.00%	3.00%
Non-US
Change in plan assets
Employer contributions	3	22	$ 22	$ 23
Non-US | Pension Plan
Change in benefit obligation
Benefit obligation as of beginning of year			573	536
Service cost	2	5	7	6
Interest cost	$ 3	7	5	10
Actuarial loss (gain)			(34)	76
Benefits paid			(21)	(22)
Foreign currency exchange rate changes			42	(32)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement			1	(1)
Benefit obligation as of end of year		536	573	573
Change in plan assets
Fair value of plan assets as of beginning of year			15	15
Actual return on plan assets			0	1
Employer contributions			22	23
Benefits paid			(21)	(22)
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)			2	(1)
Defined Benefit Plan, Plan Assets, Payment for Settlement			0	(1)
Fair value of plan assets as of end of period		$ 15	18	15
Underfunded status at end of period			(555)	(558)
Amount recognized in the Consolidated Balance Sheets consists of:
Noncurrent assets			1	1
Liability, Defined Benefit Plan, Current			(25)	(19)
Accrued benefit liability, noncurrent			(531)	(540)
Net amount recognized			(555)	(558)
Amount recognized in Accumulated other comprehensive loss (pre-tax) consists of:
Net actuarial loss (gain)			(22)	(55)
Net amount recognized			$ 22	$ 55
Weighted average assumptions used to determine benefit obligations
Discount rate	1.52%		0.86%	0.87%
Rate of compensation increase			2.60%	2.59%

Benefit Obligations - Excess of

Benefit Obligations - Excess of Plan Assets (Details) - Pension Plan - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
U.S.
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation for all plans	$ 1,145	$ 1,134
Plans with accumulated benefit obligation in excess of plan assets
Projected benefit obligation	1,145	1,134
Accumulated benefit obligation	1,145	1,134
Fair value of plan assets	927	915
Non-US
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation for all plans	555	555
Plans with accumulated benefit obligation in excess of plan assets
Projected benefit obligation	567	568
Accumulated benefit obligation	549	550
Fair value of plan assets	$ 12	$ 9

Benefit Obligations - Future Pa

Benefit Obligations - Future Payments (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.69%
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)				$ 25
2019	$ 17			17
2021	18			18
2022	19			19
2023	19			19
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	20			20
2024-2028	107			107
Total	$ 200			$ 200
U.S. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%			100.00%	100.00%
Discount rate	2.50%	3.19%	3.29%	2.84%	3.94%
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 18			$ 18
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)				66
2019	74			74
2021	73			73
2022	73			73
2023	72			72
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	71			71
2024-2028	338			338
Total	701			701
U.S. | Postretirement Health Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
2019	$ 11			$ 11
U.S. | Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%			100.00%	100.00%
Discount rate		3.37%	3.39%	2.18%	4.02%
Non-US | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%			100.00%	100.00%
Discount rate	0.86%	1.22%	1.92%	0.87%	1.92%
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 24			$ 24
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)				2
2019	24			24
2021	24			24
2022	23			23
2023	23			23
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	24			24
2024-2028	136			136
Total	$ 254			$ 254

Benefit Obligations - Component

Benefit Obligations - Components of the Pension and Post-Retirement Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Post-retirement Benefits
Weighted average assumptions used to determine net periodic benefit cost
Discount rate	2.69%
U.S. | Pension Plan
Components of net periodic benefit (credit) cost
Service cost		$ 1	$ 3	$ 4	$ 3
Interest cost		22	28	29	40
Expected return on plan assets		(38)	(51)	(55)	(60)
Amortization of actuarial loss		20	0	0	0
Net periodic benefit cost (credit)		$ 5	$ (20)	$ (22)	$ (17)
Weighted average assumptions used to determine net periodic benefit cost
Discount rate	2.50%	3.19%	3.29%	2.84%	3.94%
Expected return on plan assets		7.75%	7.65%	6.40%	7.00%
Rate of compensation increase		4.00%	4.00%	3.00%	4.00%
U.S. | Post-retirement Benefits
Components of net periodic benefit (credit) cost
Service cost		$ 0	$ 1	$ 1	$ 1
Interest cost		3	11	11	14
Expected return on plan assets		(2)	(8)	(10)	(9)
Amortization of prior service cost		(3)	0	(1)	0
Amortization of actuarial loss		2	0	0	(1)
Net periodic benefit cost (credit)		$ 0	$ 4	$ 1	$ 5
Weighted average assumptions used to determine net periodic benefit cost
Discount rate		3.37%	3.39%	2.18%	4.02%
Expected return on plan assets		5.90%	5.50%	5.50%	5.50%
Rate of compensation increase		4.00%	4.00%	3.00%	4.00%
Non-US | Pension Plan
Components of net periodic benefit (credit) cost
Service cost		$ 2	$ 5	$ 7	$ 6
Interest cost		3	7	5	10
Expected return on plan assets		(1)	0	(1)	(1)
Amortization of actuarial loss		2	0	0	0
Net periodic benefit cost (credit)		$ 6	$ 12	$ 11	$ 15
Weighted average assumptions used to determine net periodic benefit cost
Discount rate	0.86%	1.22%	1.92%	0.87%	1.92%
Expected return on plan assets		1.82%	3.68%	3.72%	3.67%
Rate of compensation increase		3.45%	3.62%	2.59%	2.58%

Benefit Obligations - Other Cha

Benefit Obligations - Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Loss (Details) - USD ($)	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
U.S. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	$ 0	$ (15,000,000)	$ 31,000,000	$ 94,000,000
Amortization of actuarial loss	(20,000,000)	0	0	0
Reorganization adjustments	(1,147,000,000)	0	0	0
Total recognized in Other comprehensive (loss) income	(1,167,000,000)	(15,000,000)	31,000,000	94,000,000
Total recognized in net periodic benefit cost and Other comprehensive income (loss)	(722,000,000)	(35,000,000)	9,000,000	77,000,000
Plan of Reorganization settlement recognized in Reorganization	(440,000,000)
U.S. | Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	0	(34,000,000)	20,000,000	36,000,000
Prior service credit	0	0	0	(7,000,000)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	3,000,000	0	1,000,000	0
Amortization of actuarial loss	(2,000,000)	0	0	1,000,000
Reorganization adjustments	(40,000,000)	0	0	0
Total recognized in Other comprehensive (loss) income	(39,000,000)	(34,000,000)	21,000,000	30,000,000
Total recognized in net periodic benefit cost and Other comprehensive income (loss)	2,000,000	(30,000,000)	22,000,000	35,000,000
Plan of Reorganization settlement recognized in Reorganization	(43,000,000)
Non-US | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	22,000,000	(19,000,000)	(33,000,000)	76,000,000
Foreign currency exchange rate changes	0	0	0	(2,000,000)
Amortization of actuarial loss	(2,000,000)	0	0	0
Reorganization adjustments	(163,000,000)	0	0	0
Total recognized in Other comprehensive (loss) income	(143,000,000)	(19,000,000)	(33,000,000)	74,000,000
Total recognized in net periodic benefit cost and Other comprehensive income (loss)	(137,000,000)	$ (7,000,000)	$ (22,000,000)	$ 89,000,000
Plan of Reorganization settlement recognized in Reorganization	$ 0

Benefit Obligations - Pension P

Benefit Obligations - Pension Plan Allocation (Details)	Sep. 30, 2020	Sep. 30, 2019
U.S. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	100.00%	100.00%
Long-term Target	100.00%
U.S. | Pension Plan | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	29.00%	29.00%
Long-term Target	34.00%
U.S. | Pension Plan | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	52.00%	52.00%
Long-term Target	52.00%
U.S. | Pension Plan | Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	6.00%	7.00%
Long-term Target	6.00%
U.S. | Pension Plan | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	5.00%	6.00%
Long-term Target	6.00%
U.S. | Pension Plan | Commodities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	2.00%	2.00%
Long-term Target	2.00%
U.S. | Pension Plan | Other
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	6.00%	4.00%
Long-term Target	0.00%
U.S. | Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	100.00%	100.00%
Long-term Target	100.00%
U.S. | Post-retirement Benefits | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	34.00%	40.00%
Long-term Target	35.00%
U.S. | Post-retirement Benefits | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	66.00%	60.00%
Long-term Target	65.00%
Non-US | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	100.00%	100.00%
Non-US | Pension Plan | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	22.00%	27.00%
Non-US | Pension Plan | Asset Allocation Fund
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	11.00%	13.00%
Non-US | Pension Plan | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	67.00%	60.00%

Benefit Obligations - Fair Valu

Benefit Obligations - Fair Value of the U.S. Pension Plans Assets by Asset Class (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Long duration fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	66.00%
U.S. equity
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	24.00%
Non-U.S. equity
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	10.00%
Post-retirement Benefits | Investments measured at net asset value:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 206	$ 191
Post-retirement Benefits | Insurance Contracts | Investments measured at net asset value:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	206	191
U.S. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 927	$ 915	$ 881
Plan asset allocations	100.00%	100.00%
U.S. | Pension Plan | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 927	$ 915
U.S. | Pension Plan | Level 1 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	(2)
U.S. | Pension Plan | Level 2 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	132	125
U.S. | Pension Plan | Level 3 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Pension Plan | Total | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	132	123
U.S. | Pension Plan | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	790	787
U.S. | Pension Plan | U.S. Government debt securities | Level 1 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Pension Plan | U.S. Government debt securities | Level 2 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	132	125
U.S. | Pension Plan | U.S. Government debt securities | Level 3 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Pension Plan | U.S. Government debt securities | Total | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	132	125
U.S. | Pension Plan | Derivative instruments | Level 1 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	(2)
U.S. | Pension Plan | Derivative instruments | Level 2 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Pension Plan | Derivative instruments | Level 3 | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. | Pension Plan | Derivative instruments | Total | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ (2)
U.S. | Pension Plan | Real estate
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	5.00%	6.00%
U.S. | Pension Plan | Real estate | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 50	$ 55
U.S. | Pension Plan | Private equity | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	4
U.S. | Pension Plan | Multi-strategy hedge funds | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	56	65
U.S. | Pension Plan | Cash equivalents | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	46	37
U.S. | Pension Plan | Long duration fixed income | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	327	328
U.S. | Pension Plan | High-yield debt | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19	19
U.S. | Pension Plan | U.S. equity | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	154	144
U.S. | Pension Plan | Non-U.S. equity | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	83	92
U.S. | Pension Plan | Emerging market equity | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 33	$ 29
U.S. | Pension Plan | Commodities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	2.00%	2.00%
U.S. | Pension Plan | Commodities | Investments measured at net asset value: | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 20	$ 14
U.S. | Pension Plan | Other plan assets, net | Other Investments Not Carried At Fair Value Or Measured At NAV | Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 5	$ 5
U.S. | Pension Plan | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	52.00%	52.00%
U.S. | Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 206	$ 191	178
Plan asset allocations	100.00%	100.00%
U.S. | Post-retirement Benefits | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	66.00%	60.00%
Non-US | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 18	$ 15	$ 15
Plan asset allocations	100.00%	100.00%
Non-US | Pension Plan | Investments measured at net asset value:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 18	$ 15
Non-US | Pension Plan | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	22.00%	27.00%
Non-US | Pension Plan | Debt Securities | Investments measured at net asset value:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 4	$ 4
Non-US | Pension Plan | Asset Allocation | Investments measured at net asset value:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 2	$ 2
Non-US | Pension Plan | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocations	67.00%	60.00%
Non-US | Pension Plan | Insurance Contracts | Investments measured at net asset value:
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 12	$ 9

Share-based Compensation (Detai

Share-based Compensation (Details) - USD ($)	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Nov. 13, 2019	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 19,000,000	$ 30,000,000	$ 25,000,000
Tax benefit from compensation expense	$ 0	1,000,000	2,000,000	2,000,000
Accelerated compensation cost	3,000,000
Share-based compensation	$ 0	$ 19,000,000	$ 30,000,000	$ 25,000,000
2019 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)			14,407,473
Award vesting period			3 years
Common Stock, Capital Shares Reserved for Future Issuance			18,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period			3 years
2019 Omnibus Inducement Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance						1,700,000
Director | 2019 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			1 year
Maximum award			$ 750,000
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares per award					1
Nonvested instruments (in shares)	369,584,000,000		2,694	2,797
Grants in period, weighted average grant date fair value (in dollars per share)	$ 0	$ 16.11	$ 12.42	$ 15.29
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			0	0
Options outstanding (in shares)			942	925
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value		$ 1,000,000	$ 2,000,000	$ 4,000,000
Time-Based Stock Option Awards | Amended And Restated Two Thousand Seven Equity Incentive Plan [Member] | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Time-Based Stock Option Awards | Amended And Restated Two Thousand Seven Equity Incentive Plan [Member] | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Employee Stock [Member] | Amended And Restated Two Thousand Seven Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	0
Expiration period					10 years
Options outstanding (in shares)							19,842,268,000,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)		$ 0	$ 13.69	$ 17.39

Share-based Compensation - Valu

Share-based Compensation - Valuations Assumptions (Details) - $ / shares	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Market-Based Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility (percent)				53.76%
Risk-free rate (percent)				2.45%
Dividend yield (percent)				0.00%
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in dollars per share)	$ 19.46		$ 11.38	$ 21.66
Volatility (percent)	56.59%	49.67%	56.76%
Term (years)	6 years 7 months 24 days	5 years 10 months 9 days	5 years 11 months 19 days
Risk-free rate (percent)	2.35%	2.72%	1.71%
Dividend yield (percent)	0.00%	0.00%	0.00%

Share-based Compensation - Opti

Share-based Compensation - Options, Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Dec. 15, 2017	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, grants in period (in shares)				164	0
Dividend yield (percent)	0.00%		0.00%	0.00%
Options, grants in period, weighted average grant date fair value (in dollars per share)				$ 11.38
Options outstanding (in shares)				942	925
Options outstanding, weighted average exercise price (in dollars per share)				$ 18.13	$ 19.59
Options exercised (in shares)				0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value			$ 8.18	$ 6.11
Compensation cost not yet recognized				$ 1
Stock options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition of compensation cost				2 years 4 months 24 days
Stock options | Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition of compensation cost				1 year 6 months
Time-Based Stock Option Awards | Maximum | Amended And Restated Two Thousand Seven Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		4 years
Time-Based Stock Option Awards | Minimum | Amended And Restated Two Thousand Seven Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years

Share-based Compensation - Op_2

Share-based Compensation - Options Outstanding (Details) - Stock options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Options (In thousands)
Granted (in shares)	164	0
Exercised (in shares)	0	0
Forfeited (in shares)	(147)
Outstanding, ending balance (in shares)	942	925
Options, grants in period, weighted average grant date fair value (in dollars per share)	$ 11.38
Options, Exercisable at September 30, 2018 (Successor) (in shares)	715,000
Weighted Average Exercise Price
Forfeited or expired (in dollars per share)	$ 19.84
Outstanding at September 30, 2018 (Successor) (in dollars per share)	18.13	$ 19.59
Weighted Average Exercise Price, Exercisable at September 30, 2018 (Successor) (in dollars per share)	$ 19.54
Weighted Average Remaining Contractual Term (in years)
Weighted Average Remaining Contractual Term (in years) Outstanding at September 30, 2018 (Successor)	7 years 3 months 18 days
Weighted Average Remaining Contractual Term (in years), Exercisable at September 30, 2018 (Successor)	6 years 10 months 24 days
Aggregate Intrinsic Value, Outstanding at September 30, 2018 (Successor)	$ 625
Aggregate Intrinsic Value, Exercisable at September 30, 2018 (Successor)	$ 0

Share-based Compensation - Nonv

Share-based Compensation - Nonvested Restricted Stock Units (Details) - Restricted stock units - shares	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 15, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	2,128
Vested (in shares)	(1,533)
Forfeited (in shares)	(698)
Non-vested shares, ending balance (in shares)	2,694	2,797	369,584,000,000

Share-based Compensation - RSU,

Share-based Compensation - RSU, Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 19	$ 30	$ 25
Share-based Payment Arrangement, Noncash Expense	$ 0	$ 19	30	$ 25
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized			$ 31
Grants in period, weighted average grant date fair value (in dollars per share)	$ 0	$ 16.11	$ 12.42	$ 15.29
Nonvested instruments (in shares)	369,584,000,000		2,694	2,797
Nonvested, weighted average grant date fair value (in dollars per share)			$ 13.32	$ 15.60
Granted (in shares)			2,128
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value			$ 15.31
Vested (in shares)			1,533
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value			$ 15.30
Instruments vested in period, fair value		$ 6	$ 23	$ 27
Market-Based Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)		$ 0	$ 0	$ 11.18
Maximum | Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition of compensation cost			2 years 10 months 24 days
Weighted Average | Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition of compensation cost			2 years

Share-based Compensation - PRSU

Share-based Compensation - PRSU, Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 19	$ 30	$ 25
Share-based Compensation by Share-based Payment Award, Fair Value Assumptions			The grant date fair value of the Performance PRSUs was determined using a Monte Carlo simulation model that incorporated multiple valuation assumptions, including the probability of achieving the total shareholder return market condition and the following assumptions presented on a weighted-average basis: Fiscal years ended September 30, 2020 2019 Expected volatility (1) 55.75 % 53.00 % Risk-free interest rate (2) 1.61 % 2.46 % Dividend yield (3) — % — % (1) Expected volatility based on a blend of Company and peer group company historical data adjusted for the Company's leverage. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the remaining Performance Period as of the grant date. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends. Fiscal year ended Expected volatility (1) 53.76 % Risk-free interest rate (2) 2.45 % Dividend yield (3) — % (1) Expected volatility based on a blend of Company and peer group company historical data adjusted for the Company's leverage. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the remaining Performance Period as of the grant date. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends. Fiscal year ended Period from December 16, 2017 Emergence Date Exercise price $ 11.38 $ 21.66 $ 19.46 Expected volatility (1) 56.76 % 49.67 % 56.59 % Expected life (in years) (2) 5.97 5.86 6.65 Risk-free interest rate (3) 1.71 % 2.72 % 2.35 % Dividend yield (4) — % — % — % (1) Expected volatility based on peer group companies adjusted for the Company's leverage. (2) Expected life based on the vesting terms of the option and a contractual life of ten years. (3) Risk-free interest rate based on U.S. Treasury yields with a term equal to the expected option term. (4) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends.
The weighted average grant date assumptions used in calculating the fair value of options granted			The grant date fair value was determined using a Black-Scholes option pricing model with the following average grant date assumptions: Fiscal year ended Expected volatility (1) 93.51 % Risk-free interest rate (2) 0.13 % Dividend yield (3) — % (1) Expected volatility based on the Company's historical data. (2) Risk-free interest rate based on U.S. Treasury yields with a term equal to the length of the offering period. (3) Dividend yield was assumed to be zero as the Company does not anticipate paying dividends.
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)	$ 0	$ 16.11	$ 12.42	$ 15.29
Nonvested instruments (in shares)	369,584,000,000		2,694	2,797
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			2,128
Forfeited (in shares)			(698)
Nonvested, weighted average grant date fair value (in dollars per share)			$ 13.32	$ 15.60
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value			$ 15.30
Compensation cost not yet recognized			$ 31
Restricted stock units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition of compensation cost			2 years 10 months 24 days
Restricted stock units | Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition of compensation cost			2 years
Market-Based Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)		0	$ 0	$ 11.18
Volatility (percent)				53.76%
Risk-free rate (percent)				2.45%
Dividend yield (percent)				0.00%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)		$ 0	$ 13.69	$ 17.39
Volatility (percent)			55.75%	53.00%
Risk-free rate (percent)			1.61%	2.46%
Dividend yield (percent)			0.00%	0.00%
PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)			$ 13.69
Nonvested instruments (in shares)			588,000	274,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			662,000
Vested (in shares)			(314,000)
Forfeited (in shares)			(34,000)
Nonvested, weighted average grant date fair value (in dollars per share)			$ 12.53	$ 11.18
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value			$ 13.29
Compensation cost not yet recognized			$ 5
Share-based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Change in shares due to performance, Weighted Average Grant Date Fair Value			$ 13.71
PRSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition of compensation cost			2 years 4 months 24 days
PRSUs | Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for recognition of compensation cost			2 years 1 month 6 days

Share-based Compensation - ESPP

Share-based Compensation - ESPP Narrative (Details) - USD ($)	10 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 19,000,000	$ 30,000,000	$ 25,000,000
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility (percent)			93.51%
Risk-free rate (percent)			0.13%
Dividend yield (percent)			0.00%
Employee Stock [Member] | Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		5,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date		15.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate		10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Shares per Offering Period		$ 6,250
Share-based compensation expense		$ 3,000,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans		204,445
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased		5,295,555
Grants in period, weighted average grant date fair value (in dollars per share)		$ 4.99
Compensation cost not yet recognized		$ 400,000
Period for recognition of compensation cost		2 months 12 days
Market-Based Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)	$ 0	$ 0	$ 11.18
Volatility (percent)			53.76%
Risk-free rate (percent)			2.45%
Dividend yield (percent)			0.00%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period, weighted average grant date fair value (in dollars per share)	$ 0	$ 13.69	$ 17.39
Volatility (percent)		55.75%	53.00%
Risk-free rate (percent)		1.61%	2.46%
Dividend yield (percent)		0.00%	0.00%

Capital Stock - Narrative (Deta

Capital Stock - Narrative (Details) - USD ($)	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Oct. 31, 2019	Oct. 01, 2019	Nov. 14, 2018	Jun. 11, 2018
Class of Stock [Line Items]
Preferred stock, shares authorized			55,000,000	55,000,000
Preferred stock, par value (in usd per share)			$ 0.01	$ 0.01
Preferred shares issued			125,000
Preferred stock, shares outstanding				0	125,000
Common stock, shares authorized			550,000,000	550,000,000
Common stock, par value (usd per share)			$ 0.01	$ 0.01
Common stock, shares issued	110,000,000		83,278,383	111,046,085
Common stock, shares outstanding			83,278,383	111,033,405
Common stock, issued for GUC (shares)	200,000			12,680
Exercise price of warrants (in usd per share)	$ 25.55
Class of warrant or right, number of securities called by each warrant or right (in shares)	5,645,200
Preferred stock, accretion of discount			$ 4,000,000
Warrants issued (in shares)								12,600,000
Warrant Repurchase Program, Number of Securities Called by Warrants or Rights, Authorized Amount							$ 15,000,000
Warrant Repurchase Program, Number of Securities Called by Warrants or Rights, Number of Warrants Repurchased			0
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 0	$ 0	$ 121,000,000	$ 0
Strategic Partnership Interest on As-Converted Basis			9.00%
Preferred Stock, Value, Issued			$ 128,000,000
Dividends Payable			$ 3,000,000
Stock Repurchase Program, Authorized Amount						$ 500,000,000
Stock Repurchased During Period, Shares			28,923,664
Stock Repurchased During Period, Value			$ 11.41
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 170,000,000
Strategic Partnership, Minimum Shares Required for Consent Rights			4,759,339
Preferred Stock, Dividend Rate, Percentage			3.00%
Temporary equity			$ 128,000,000	$ 0
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, par value (in usd per share)			$ 1,000
Preferred shares issued			125,000	0
Preferred stock, shares outstanding			125,000	0
Proceeds from Issuance of Preferred Stock and Preference Stock			$ 125,000,000
Price per share of common stock (in usd per share)			$ 16
Temporary equity	$ 0
As Previously Reported
Class of Stock [Line Items]
Common stock, shares issued	110,000,000

Net Income (Loss) Per Common _3

Net Income (Loss) Per Common Share - Reconciliation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2017
Numerator
Net (loss) income	$ 2,977	$ 37	$ 9	$ (672)	$ (54)	$ (34)	$ (633)	$ (13)	$ 9	$ 287	$ (680)	$ (671)	$ 2,977
Dividends and accretion to preferred stockholders	(6)									0	(7)	0
Undistributed (loss) income	$ (2,971)									$ (287)	$ (687)	$ (671)
Percentage allocated to common stockholders	86.90%									100.00%	100.00%	100.00%
Numerator for basic and diluted (loss) earnings per common share	$ 2,582									$ 287	$ (687)	$ (671)
Weighted average shares outstanding
Denominator for basic earnings per weighted average common shares (in shares)	497.3									109.9	92.2	110.8
Effect of dilutive securities
Denominator for diluted earnings (loss) per weighted average common shares (in shares)	497.3									111.1	92.2	110.8
(Loss) earnings per common share
Basic (in usd per share)	$ 5.19	$ 0.40	$ 0.08	$ (7.24)	$ (0.54)	$ (0.31)	$ (5.70)	$ (0.12)	$ 0.08	$ 2.61		$ (6.06)
Diluted (in usd per share)	$ 5.19	$ 0.39	$ 0.08	$ (7.24)	$ (0.54)	$ (0.31)	$ (5.70)	$ (0.12)	$ 0.08	$ 2.58		$ (6.06)
Weighted average number of shares - basic (in shares)	497.3									109.9	92.2	110.8
Basic weighted average common stock and common stock equivalents (preferred shares) (in shares)	572.4									109.9		110.8
Restricted stock units
Effect of dilutive securities
Share-based payment arrangements (in shares)	0									1.2	0	0

Net Income (Loss) Per Common _4

Net Income (Loss) Per Common Share - Narrative (Details) - $ / shares shares in Thousands	10 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Jun. 11, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Class of Warrant or Right, Outstanding				12,600
Conversion price (in usd per share)				$ 27.76
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,100	900	900
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	200	2,700	2,800
Performance Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		1,000	500
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	5,600	5,600	5,600
Employee Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		200
Series A Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		100

Operating Segments - Summarized

Operating Segments - Summarized Financial Information of Operating Segments (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information
REVENUE	$ 604	$ 755	$ 721	$ 682	$ 715	$ 723	$ 717	$ 709	$ 738	$ 2,247	$ 2,873	$ 2,887
GROSS PROFIT	362	418	397	371	394	392	390	386	407	1,143	1,580	1,575
OPERATING EXPENSES
Selling, general and administrative	264									888	1,013	1,001
Research and development	38									172	207	204
Amortization of intangible assets	10									127	161	162
Impairment charges	0									0	624	659
Restructuring charges, net	14									81	30	22
TOTAL OPERATING EXPENSES	326									1,268	2,035	2,048
OPERATING (LOSS) INCOME	36	74	$ 53	$ (597)	$ 15	52	$ (613)	$ 38	$ 50	(125)	(455)	(473)
INTEREST EXPENSE, OTHER INCOME (EXPENSE), NET AND REORGANIZATION ITEMS, NET	3,400									(134)	(163)	(196)
(LOSS) INCOME BEFORE INCOME TAXES	3,436									(259)	(618)	(669)
Total Assets		6,231				6,950					6,231	6,950
Goodwill impairment											624	657
Products & Solutions
Segment Reporting Information
REVENUE											1,074	1,228
OPERATING EXPENSES
Goodwill impairment											624	657
Services
Segment Reporting Information
REVENUE											1,805	1,680
OPERATING EXPENSES
Goodwill impairment											0	0
Unallocated
Segment Reporting Information
REVENUE											(6)	(21)
Operating Segments | Products & Solutions
Segment Reporting Information
REVENUE	253									1,052	1,074	1,228
GROSS PROFIT	169									696	669	791
OPERATING EXPENSES
Total Assets		31				662					31	662
Operating Segments | Services
Segment Reporting Information
REVENUE	351									1,401	1,805	1,680
GROSS PROFIT	196									843	1,092	996
OPERATING EXPENSES
Total Assets		1,501				1,504					1,501	1,504
Unallocated | Unallocated
Segment Reporting Information
REVENUE	0									(206)	(6)	(21)
GROSS PROFIT	$ (3)									$ (396)	(181)	(212)
OPERATING EXPENSES
Total Assets		$ 4,699				$ 4,784					$ 4,699	$ 4,784

Operating Segments - Revenue by

Operating Segments - Revenue by Geographic Area (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
REVENUE	$ 604	$ 755	$ 721	$ 682	$ 715	$ 723	$ 717	$ 709	$ 738	$ 2,247	$ 2,873	$ 2,887
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
REVENUE	331									1,184	1,640	1,553
International
Revenues from External Customers and Long-Lived Assets [Line Items]
REVENUE	273									1,063	1,233	1,334
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
REVENUE	166									603	714	753
APAC—Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
REVENUE	57									256	296	327
Americas International—Canada and Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
REVENUE	$ 50									$ 204	$ 223	$ 254

Operating Segments - Long-lived

Operating Segments - Long-lived Assets by Geographic Area (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 268	$ 255
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	191	184
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	77	71
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	57	54
APAC—Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	13	10
Americas International—Canada and Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 7	$ 7

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive (Loss) Income - Components (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ (5,013)	$ 1,668	$ 1,300	$ 2,051
OCI, before Reclassifications, before Tax, Attributable to Parent	(21)	36	(137)	(249)
Amounts reclassified to earnings	16		62	10
Pension settlement	721
(Provision for) benefit from income taxes	(58)	(18)	3	48
Ending Balance	1,668	2,051	236	1,300
Eliminations
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		790
Ending Balance	790
Change in Unamortized Pension, Post-retirement and Postemployment Benefit-related Items
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(1,375)	0	(106)	51
OCI, before Reclassifications, before Tax, Attributable to Parent	(24)	70	(2)	(186)
Amounts reclassified to earnings	16		0	0
Pension settlement	721
(Provision for) benefit from income taxes	(58)	(19)	0	29
Ending Balance	0	51	(108)	(106)
Stockholders' Equity Attributable to Parent, Before Elimination Of Predecessor Company Accumulated Other Comprehensive Loss	(720)
Change in Unamortized Pension, Post-retirement and Postemployment Benefit-related Items | Eliminations
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		720
Ending Balance	720
Foreign Currency Translation
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(72)	0	(7)	(31)
OCI, before Reclassifications, before Tax, Attributable to Parent	3	(31)	(66)	24
Amounts reclassified to earnings	0		27	0
Pension settlement	0
(Provision for) benefit from income taxes	0	0	0	0
Ending Balance	0	(31)	(46)	(7)
Stockholders' Equity Attributable to Parent, Before Elimination Of Predecessor Company Accumulated Other Comprehensive Loss	(69)
Foreign Currency Translation | Eliminations
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		69
Ending Balance	69
Unrealized Loss on Interest Rate Swaps
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	0	0	(60)	(2)
OCI, before Reclassifications, before Tax, Attributable to Parent	0	(3)	(69)	(87)
Amounts reclassified to earnings	0		35	10
Pension settlement	0
(Provision for) benefit from income taxes	0	1	3	19
Ending Balance	0	(2)	(91)	(60)
Stockholders' Equity Attributable to Parent, Before Elimination Of Predecessor Company Accumulated Other Comprehensive Loss	0
Unrealized Loss on Interest Rate Swaps | Eliminations
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		0
Ending Balance	0
Other
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(1)	0	0	0
OCI, before Reclassifications, before Tax, Attributable to Parent	0	0	0	0
Amounts reclassified to earnings	0		0	0
Pension settlement	0
(Provision for) benefit from income taxes	0	0	0
Ending Balance	0	0	0	0
Stockholders' Equity Attributable to Parent, Before Elimination Of Predecessor Company Accumulated Other Comprehensive Loss	(1)
Other | Eliminations
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		1
Ending Balance	1
Accumulated Other Comprehensive (Loss) Income
Increase (Decrease) in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(1,448)	0	(173)	18
Ending Balance	0	$ 18	$ (245)	$ (173)
Stockholders' Equity Attributable to Parent, Before Elimination Of Predecessor Company Accumulated Other Comprehensive Loss	$ (790)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive (Loss) Income - Narrative (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified to earnings	$ 16	$ 62	$ 10
Unrealized Loss on Interest Rate Swaps
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified to earnings	$ 0	$ 35	$ 10

Related Party Transactions (Det

Related Party Transactions (Details)	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2020USD ($)director	Sep. 30, 2019USD ($)	Sep. 30, 2015USD ($)
Related Party Transaction [Line Items]
Number of directors | director			7
Management Fee Expense	$ 0
Sponsor Fees	0
Messrs. Mohebbi and Rittenmeyer
Related Party Transaction [Line Items]
Amount of transaction			$ 800,000
The Sponsors
Related Party Transaction [Line Items]
Cost of goods and services sold	15,000,000
Revenue from related parties	10,000,000
Commerical Real Estate Services Firm
Related Party Transaction [Line Items]
Cost of goods and services sold	5,000,000
Flex Ltd | Board of Directors Chairman
Related Party Transaction [Line Items]
Accounts payable, related parties			3,000,000	$ 6,000,000
Flex Ltd | Purchased Goods And Services From Flex Ltd. | Board of Directors Chairman
Related Party Transaction [Line Items]
Cost of goods and services sold	6,000,000	$ 19,000,000	23,000,000	$ 29,000,000
Flex Ltd | Sales [Member] | Board of Directors Chairman
Related Party Transaction [Line Items]
Revenue from related parties			1,000,000
Flex Ltd | Accounts Receivable | Board of Directors Chairman
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party			1,000,000
TPG Capital Management LP | Monitoring Fee | Affiliated Entity
Related Party Transaction [Line Items]
Reduction of related party transaction, amount					$ 1,325,000
Alight Ltd [Member] | Director
Related Party Transaction [Line Items]
Accounts payable, related parties			1,000,000
Alight Ltd [Member] | Purchased Goods And Services From Flex Ltd. | Director
Related Party Transaction [Line Items]
Cost of goods and services sold			$ 5,000,000
Koopid Inc | Purchased Goods And Services From Flex Ltd.
Related Party Transaction [Line Items]
Cost of goods and services sold		1,000,000
Tenet Healthcare | Sales [Member] | Director
Related Party Transaction [Line Items]
Revenue from related parties		1,000,000
AIG [Member] | Sales [Member] | Director
Related Party Transaction [Line Items]
Revenue from related parties	2,000,000	$ 5,000,000
Silver Lake and TPG | Affiliated Entity
Related Party Transaction [Line Items]
Management Fee Expense	7,000,000
Sponsor Fees	$ 0
Non-Employee Director
Related Party Transaction [Line Items]
Number of directors | director			6

Commitments and Contingencies -

Commitments and Contingencies - General (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Loss Contingencies [Line Items]
Legal Fees	$ 37	$ 0	$ 0	$ 0
Amount reserved for product warranties		$ 2	$ 2

Commitments and Contingencies_2

Commitments and Contingencies - Product Warranties (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Product Warranty Liability [Line Items]
Product warranties, maximum term			2 years
Amount reserved for product warranties			$ 2	$ 2
Product warranty expense	$ 1	$ 2	$ 4	$ 3

Commitments and Contingencies_3

Commitments and Contingencies - Letters of Credit and Guarantees (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 15, 2017
Line of Credit Facility [Line Items]
Letters of credit, maximum amount		$ 150
Restricted cash	$ 4
Standby Letters of Credit
Line of Credit Facility [Line Items]
Letters of credit, maximum amount	$ 52

Commitments and Contingencies_4

Commitments and Contingencies - Transactions with Nokia (Details) $ in Millions	12 Months Ended
	Sep. 30, 2020USD ($)
Indemnification Agreement
Loss Contingencies [Line Items]
Threshold amount of contribution and distribution agreement	$ 50

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2017
Effect of Fourth Quarter Events [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 604	$ 755	$ 721	$ 682	$ 715	$ 723	$ 717	$ 709	$ 738	$ 2,247	$ 2,873	$ 2,887
Gross Profit	362	418	397	371	394	392	390	386	407	1,143	1,580	1,575
Operating Income (Loss)	36	74	53	(597)	15	52	(613)	38	50	(125)	(455)	(473)
Income Tax Expense (Benefit)	(459)	20	(20)	(37)	(25)	(32)	27	6	(3)	546	(62)	(2)
Net Income (Loss) Attributable to Parent	$ 2,977	37	9	(672)	(54)	(34)	(633)	(13)	9	$ 287	$ (680)	$ (671)	$ 2,977
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS		$ 33	$ 7	$ (673)	$ (59)	$ (34)	$ (633)	$ (13)	$ 9
Net income (loss) per common share - basic (in usd per share)	$ 5.19	$ 0.40	$ 0.08	$ (7.24)	$ (0.54)	$ (0.31)	$ (5.70)	$ (0.12)	$ 0.08	$ 2.61		$ (6.06)
Net income (loss) per common share - diluted (in usd per share)	$ 5.19	$ 0.39	$ 0.08	$ (7.24)	$ (0.54)	$ (0.31)	$ (5.70)	$ (0.12)	$ 0.08	$ 2.58		$ (6.06)

Condensed Financial Informati_3

Condensed Financial Information of Parent Company - Condensed Balance Sheets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Dec. 15, 2017	Sep. 30, 2017
ASSETS
TOTAL ASSETS	$ 6,231	$ 6,950
LIABILITIES
TOTAL LIABILITIES	5,867	5,650
Temporary equity	128	0
TOTAL STOCKHOLDERS' EQUITY	236	1,300	$ 2,051	$ 1,668	$ (5,013)
TOTAL LIABILITIES AND STOCKHOLDER'S DEFICIENCY	6,231	6,950
Parent Company
ASSETS
Investment in Avaya Inc.	888	1,604
TOTAL ASSETS	888	1,604
LIABILITIES
Long-term debt	291	273
Other liabilities	233	31
TOTAL LIABILITIES	524	304
Commitments and contingencies (Note 22)
Temporary equity	128	0
TOTAL STOCKHOLDERS' EQUITY	236	1,300
TOTAL LIABILITIES AND STOCKHOLDER'S DEFICIENCY	$ 888	$ 1,604

Condensed Financial Informati_4

Condensed Financial Information of Parent Company - Condensed Statements of Operations (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2017
Condensed Income Statements, Captions [Line Items]
Selling, general and administrative	$ 264									$ 888	$ 1,013	$ 1,001
Interest expense	(14)									(169)	(226)	(237)
Other (expense) income, net	(2)									35	63	41
(LOSS) INCOME BEFORE INCOME TAXES	3,436									(259)	(618)	(669)
Provision for income taxes	459	$ (20)	$ 20	$ 37	$ 25	$ 32	$ (27)	$ (6)	$ 3	(546)	62	2
Net (loss) income	$ 2,977	37	9	(672)	(54)	(34)	(633)	(13)	9	$ 287	$ (680)	$ (671)	$ 2,977
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS		$ 33	$ 7	$ (673)	$ (59)	$ (34)	$ (633)	$ (13)	$ 9
(LOSS) EARNINGS PER SHARE AVAILABLE TO COMMON STOCKHOLDERS
Basic (in usd per share)	$ 5.19	$ 0.40	$ 0.08	$ (7.24)	$ (0.54)	$ (0.31)	$ (5.70)	$ (0.12)	$ 0.08	$ 2.61		$ (6.06)
Diluted (in usd per share)	$ 5.19	$ 0.39	$ 0.08	$ (7.24)	$ (0.54)	$ (0.31)	$ (5.70)	$ (0.12)	$ 0.08	$ 2.58		$ (6.06)
Weighted average shares outstanding
Basic (in shares)	497.3									109.9	92.2	110.8
Diluted (in shares)	497.3									111.1	92.2	110.8
Parent Company
Condensed Income Statements, Captions [Line Items]
Equity in net (loss) income of Avaya Inc.	$ 2,977									$ 311	$ (616)	$ (672)
Selling, general and administrative	0									0	(35)	(3)
Interest expense	0									(3)	(26)	(25)
Other (expense) income, net	0									(21)	(3)	29
(LOSS) INCOME BEFORE INCOME TAXES	2,977									287	(680)	(671)
Provision for income taxes	0									0	0	0
Net (loss) income	2,977									287	(680)	(671)
Less: Accretion and accrued dividends on Series A preferred stock	0									0	(7)	0
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS	$ 2,977									$ 287	$ (687)	$ (671)
(LOSS) EARNINGS PER SHARE AVAILABLE TO COMMON STOCKHOLDERS
Basic (in usd per share)	$ 5.19									$ 2.61	$ (7.45)	$ (6.06)
Diluted (in usd per share)	$ 5.19									$ 2.58	$ (7.45)	$ (6.06)
Weighted average shares outstanding
Basic (in shares)	497.3									109.9	92.2	110.8
Diluted (in shares)	497.3									111.1	92.2	110.8

Condensed Financial Informati_5

Condensed Financial Information of Parent Company - Condensed Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2017
Condensed Statement of Income Captions [Line Items]
Net (loss) income	$ 2,977	$ 37	$ 9	$ (672)	$ (54)	$ (34)	$ (633)	$ (13)	$ 9	$ 287	$ (680)	$ (671)	$ 2,977
Elimination of Predecessor Company accumulated other comprehensive loss	790									0	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	658									18	(72)	(191)	$ 658
Total comprehensive (loss) income	4,425									305	(752)	(862)
Accumulated Other Comprehensive (Loss) Income
Condensed Statement of Income Captions [Line Items]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	658									18	(72)	(191)
Parent Company
Condensed Statement of Income Captions [Line Items]
Net (loss) income	2,977									287	(680)	(671)
Elimination of Predecessor Company accumulated other comprehensive loss	790									0	0	0
Total comprehensive (loss) income	$ 4,425									$ 305	$ (752)	$ (862)

Condensed Financial Informati_6

Condensed Financial Information of Parent Company - Condensed Statements of Cash Flows (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Net (loss) income	$ 2,977	$ 37	$ 9	$ (672)	$ (54)	$ (34)	$ (633)	$ (13)	$ 9	$ 287	$ (680)	$ (671)	$ 2,977
Adjustments to reconcile net (loss) income to net cash used for operating activities:
Share-based compensation	0									19	30	25
Change in fair value of emergence date warrants	0									17	3	(29)
Net cash used for operating activities	(414)									202	147	241
Net cash used for investing activities	(13)									(199)	314	(124)
Net cash provided by financing activities	(102)									273	(489)	(61)
Cash and cash equivalents at beginning of year					752				700	366	752	700
Cash and cash equivalents at end of year	366	727				752				700	727	752
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Net (loss) income	2,977									287	(680)	(671)
Adjustments to reconcile net (loss) income to net cash used for operating activities:
Share-based compensation	0									0	2	2
Amortization of Debt Issuance Costs	0									4	18	17
Change in fair value of emergence date warrants	0									17	3	(29)
Increase (Decrease) in Operating Capital	0									3	0	9
Net cash used for operating activities	0									0	(41)	0
Net cash used for investing activities	0									(314)	0	0
Net cash provided by financing activities	0									314	41	0
Net decrease in cash and cash equivalents	0									0	0	0
Cash and cash equivalents at beginning of year	0				$ 0				$ 0	0	0	0
Cash and cash equivalents at end of year	0	$ 0				$ 0				0	0	0	$ 0
Income (Loss) from Subsidiaries, before Tax	$ (2,977)									$ (311)	$ 616	$ 672

Restructuring and Related Activ

Restructuring and Related Activities (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 15, 2017	Sep. 30, 2018	Sep. 30, 2020	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	$ 14	$ 81	$ 30	$ 22
Employee Separation Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	13	70	6	19
Facility Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	$ 1	$ 11	$ 24	$ 3

Uncategorized Items - avya-2020

Label	Element	Value
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	$ 3,000,000
Reclassifications of Temporary to Permanent Equity	us-gaap_ReclassificationsOfTemporaryToPermanentEquity	1,000,000
Additional Paid-in Capital [Member]
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3,000,000
Reclassifications of Temporary to Permanent Equity	us-gaap_ReclassificationsOfTemporaryToPermanentEquity	1,000,000
Retained Earnings [Member]
Net Income (Loss) Attributable to Parent	us-gaap_NetIncomeLoss	2,977,000,000
Series A Preferred Stock [Member]
Dividends, Preferred Stock	us-gaap_DividendsPreferredStock	2,000,000
Series A Preferred Stock [Member] | Additional Paid-in Capital [Member]
Dividends, Preferred Stock	us-gaap_DividendsPreferredStock	2,000,000
Series B Preferred Stock [Member]
Dividends, Preferred Stock	us-gaap_DividendsPreferredStock	4,000,000
Series B Preferred Stock [Member] | Additional Paid-in Capital [Member]
Dividends, Preferred Stock	us-gaap_DividendsPreferredStock	$ 4,000,000