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Debt - Senior Notes and Junior Subordinated Notes (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Mar. 20, 2024
Junior subordinated notes | On or after September 30, 2026
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Junior subordinated notes | If changes in tax laws and interpretations occur
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Junior subordinated notes | If a rating agency makes certain changes relating to the equity credit criteria for securities
Debt Instrument [Line Items]
Redemption price percentage	102.00%
2025 Senior Notes | Senior notes
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Applicable basis spread over redemption price percentage	0.25%
Face amount	$ 350.0
2030 Senior Notes | Senior notes
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Applicable basis spread over redemption price percentage	0.40%
Face amount	$ 350.0
6.750% Junior Subordinated Notes due 2064 | Junior subordinated notes
Debt Instrument [Line Items]
Face amount	$ 450.0	$ 450.0
6.750% Junior Subordinated Notes due 2064 | Junior subordinated notes | On or after September 30, 2026
Debt Instrument [Line Items]
Redemption price percentage	100.00%

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