CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosure [Abstract]
Net investment hedge currency translation adjustment, tax	$ (1,739)	$ (4,531)	$ 2,837	$ (24,239)
Changes in unrealized gains on marketable securities, tax	(257)	858	607	1,395
Actuarial loss, tax	$ (3)	$ 0	$ (1)	$ 0

Amount of tax expense (benefit), before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 10A
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-Publisher FASB
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
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-URI https://asc.fasb.org//1943274/2147482790/220-10-45-12

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
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