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Subsequent Events (Details) - USD ($) $ in Thousands				2 Months Ended	3 Months Ended	12 Months Ended
Subsequent Events (Details) - USD ($) $ in Thousands	Feb. 15, 2024	Feb. 12, 2024	Jan. 24, 2024	Feb. 27, 2024	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Cash proceeds from sale of business					$ 4,100
Proceeds from sales of available-for-sale securities						$ 789,603	$ 172,947	$ 0
Equity Securities, FV-NI, Realized Loss						37,400	6,800
Proceeds from sales of available-for-sale securities						789,603	172,947	$ 0
Equity Securities, FV-NI, Realized Loss						$ 37,400	$ 6,800
Senior Notes \| Debt Instrument, Redemption, Period One
Subsequent Event [Line Items]
Debt instrument, stated interest rate, percentage					4.375%	4.375%
Subsequent Event
Subsequent Event [Line Items]
Disposal Group Not Discontinued Operation Gain Loss On Disposal Statement Of Income Extensible List Not Disclosed Flag		true
Proceeds from sales of available-for-sale securities				$ 281,300
Equity Securities, FV-NI, Realized Loss				11,300
Proceeds from sales of available-for-sale securities				281,300
Equity Securities, FV-NI, Realized Loss				$ 11,300
Subsequent Event \| Senior Notes \| Debt Instrument, Redemption, Period One
Subsequent Event [Line Items]
Repayment of long-term debt	$ 132,600
Subsequent Event \| Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Mortgage Servicing Portfolio
Subsequent Event [Line Items]
Cash proceeds from sale of business		$ 18,600
Gain recognized on sale		$ 11,900
Ametros \| Subsequent Event
Subsequent Event [Line Items]
Cash consideration			$ 350,000