Operating Segments - Summarized Financial Information of Operating Segments (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019
Segment Reporting Information
REVENUE	$ 682	$ 709	$ 1,397	$ 1,447
GROSS PROFIT	371	386	765	793
OPERATING EXPENSES
Selling, general and administrative	248	251	531	508
Research and development	51	52	103	105
Amortization of intangible assets	41	41	82	81
Restructuring charges, net	4	4	7	11
TOTAL OPERATING EXPENSES	968	348	1,347	705
OPERATING (LOSS) INCOME	(597)	38	(582)	88
INTEREST EXPENSE AND OTHER INCOME, NET	(38)	(57)	(82)	(95)
Total Assets	6,211		6,211		$ 6,950
LOSS BEFORE INCOME TAXES	(635)	(19)	(664)	(7)
Products & Solutions
Segment Reporting Information
REVENUE	245	289	543	615
Services
Segment Reporting Information
REVENUE	438	425	857	847
Operating Segments \| Products & Solutions
Segment Reporting Information
REVENUE	245	289	543	615
GROSS PROFIT	154	184	348	398
Operating Segments \| Services
Segment Reporting Information
REVENUE	438	425	857	847
GROSS PROFIT	263	255	509	510
Unallocated
Segment Reporting Information
REVENUE	(1)	(5)	(3)	(15)
GROSS PROFIT	$ (46)	$ (53)	$ (92)	$ (115)

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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