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Credit and Other Debt Agreements - Note Purchase Agreements - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended			12 Months Ended
	Feb. 29, 2024	Jun. 30, 2023	Feb. 28, 2023	Dec. 31, 2024
Series HH note [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	4.72%
Debt instrument, maturity date	Feb. 13, 2024
Operating cash to fund	$ 100.0
Series H note [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	4.58%
Debt instrument, maturity date	Feb. 27, 2024
Operating cash to fund	$ 325.0
Series N note [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate		4.13%
Debt instrument, maturity date		Jun. 24, 2023
Operating cash to fund		$ 200.0
Series CC note [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date		Jun. 13, 2024
Quarterly payments of interest, description		90 day LIBOR
Quarterly payments of interest rate		1.40%
Prepayment of debt		$ 50.0
Series E note [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate			5.49%
Debt instrument, maturity date			Feb. 10, 2023
Operating cash to fund			$ 50.0
Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Amount payable to redeem the notes, percent of the principal amount				100.00%
Discount rate used to compute the remaining scheduled payments of principal and interest				U.S. Treasury yield plus 0.5

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