Investments - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2023	Sep. 30, 2022
Subsidiary, Sale of Stock [Line Items]
Equity securities without readily determinable fair value, upward price adjustment, cumulative amount	$ 17.2	$ 17.2
PTC
Subsidiary, Sale of Stock [Line Items]
Number of shares purchased (in shares)	7,135,832	8,879,717

Amount of cumulative gain from upward price adjustment on investment in equity security without readily determinable fair value.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126980263&loc=SL75117539-209714

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant