Business Combinations - Preliminary Allocation Of The Aggregate Purchase Price (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022	Sep. 12, 2022	Apr. 01, 2022	Apr. 02, 2021	Jan. 08, 2021
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Goodwill	$ 10,217			$ 2,873	$ 2,867
Avast plc
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Accounts receivable			$ 63
Other current assets			17
Property and equipment			33
Operating lease assets			18
Intangible assets		$ 2,383	2,383
Goodwill			7,349
Other long-term asset			11
Total assets acquired			9,874
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Current liabilities			180
Contract liabilities			509
Operating lease liabilities			18
Long-term deferred tax liabilities			433
Other long-term obligations			46
Total liabilities assumed			1,186
Total purchase price			$ 8,688
Avira
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Intangible assets						$ 162
Goodwill						261
Other long-term asset						21
Current assets						12
Total assets acquired						456
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Current liabilities						29
Contract liabilities						54
Other long-term obligations						29
Total liabilities assumed						112
Total purchase price						$ 344