Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-5

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Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Amount before accretion (amortization) of purchase discount (premium) of interest income and dividend income on nonoperating securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(a),(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

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Derivatives and Hedging Activities - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative [Line Items]
Investment income	$ (272,480)	$ (167,148)	$ (761,245)	$ (468,426)
Interest Rate Swap
Derivative [Line Items]
Investment income			$ (900)	$ 0
Interest Rate Swap \| Minimum
Derivative [Line Items]
Derivative, maturities	1 year		1 year
Interest Rate Swap \| Maximum
Derivative [Line Items]
Derivative, maturities	7 years		7 years
Interest Rate Swap \| Weighted Average
Derivative [Line Items]
Derivative, maturities	5 years 9 months 18 days		5 years 9 months 18 days