Investment in Securities - Schedule of the Fair Values of Securities with Unrealized Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
AFS, Less than 12 months, Estimated Fair Value	$ 78,195	$ 456,451
AFS, Less than 12 months, Unrealized Losses	1,244	22,374
AFS, 12 months or more, Estimated Fair Value	529,657	260,284
AFS, 12 months or more, Unrealized Losses	79,282	48,259
AFS, Total Estimated Fair Value	607,852	716,735
AFS, Total Unrealized Losses	80,526	70,633
State and political subdivisions
Marketable Securities [Line Items]
AFS, Less than 12 months, Estimated Fair Value	63,256	214,919
AFS, Less than 12 months, Unrealized Losses	1,183	8,958
AFS, 12 months or more, Estimated Fair Value	149,202	47,474
AFS, 12 months or more, Unrealized Losses	24,552	13,346
AFS, Total Estimated Fair Value	212,458	262,393
AFS, Total Unrealized Losses	25,735	22,304
Mortgage-backed securities issued or guaranteed by U.S. government agencies or sponsored enterprises
Marketable Securities [Line Items]
AFS, Less than 12 months, Estimated Fair Value	0	53,732
AFS, Less than 12 months, Unrealized Losses	0	6,135
AFS, 12 months or more, Estimated Fair Value	152,435	118,017
AFS, 12 months or more, Unrealized Losses	39,806	25,101
AFS, Total Estimated Fair Value	152,435	171,749
AFS, Total Unrealized Losses	39,806	31,236
Corporate bonds
Marketable Securities [Line Items]
AFS, Less than 12 months, Estimated Fair Value	14,939	32,517
AFS, Less than 12 months, Unrealized Losses	61	3,629
AFS, 12 months or more, Estimated Fair Value	79,510	47,580
AFS, 12 months or more, Unrealized Losses	11,662	7,622
AFS, Total Estimated Fair Value	94,449	80,097
AFS, Total Unrealized Losses	11,723	11,251
Treasury securities
Marketable Securities [Line Items]
AFS, Less than 12 months, Estimated Fair Value	0	155,283
AFS, Less than 12 months, Unrealized Losses	0	3,652
AFS, 12 months or more, Estimated Fair Value	107,722	0
AFS, 12 months or more, Unrealized Losses	2,030	0
AFS, Total Estimated Fair Value	107,722	155,283
AFS, Total Unrealized Losses	2,030	3,652
Asset backed securities issued or guaranteed by U.S. government agencies or sponsored enterprises
Marketable Securities [Line Items]
AFS, Less than 12 months, Estimated Fair Value	0	0
AFS, Less than 12 months, Unrealized Losses	0	0
AFS, 12 months or more, Estimated Fair Value	40,788	47,213
AFS, 12 months or more, Unrealized Losses	1,232	2,190
AFS, Total Estimated Fair Value	40,788	47,213
AFS, Total Unrealized Losses	$ 1,232	$ 2,190

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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