Securities Available for Sale - Schedule of Contractual Maturities of AFS Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Amortized Cost
Amortized Cost, Due after 1 year through 5 years	$ 3,139,758
Amortized Cost, Due after 5 years through 10 years	45,782
Amortized Cost, Due after 10 years	380,289
Amortized Cost	3,565,829	$ 3,492,264
Fair Value
Fair Value, Due after 1 year through 5 years	3,157,085
Fair Value, Due after 5 years through 10 years	42,702
Fair Value, Due after 10 years	327,355
Fair Value	$ 3,527,142	3,452,648
Weighted-average Yield, Due after 1 year through 5 years	6.85%
Weighted-average Yield, Due after 5 years through 10 years	3.77%
Weighted-average Yield, Due after 10 years	3.05%
Weighted-average Yield	6.39%
Senior asset-backed securities related to Structured Program transactions
Amortized Cost
Amortized Cost, Due after 1 year through 5 years	$ 2,940,007
Amortized Cost	2,940,007	2,870,071
Fair Value
Fair Value, Due after 1 year through 5 years	2,962,475
Fair Value	2,962,475	2,899,824
Other asset-backed securities related to Structured Program transactions
Amortized Cost
Amortized Cost, Due after 1 year through 5 years	188,831
Amortized Cost	188,831	174,132
Fair Value
Fair Value, Due after 1 year through 5 years	184,032
Fair Value	184,032	169,948
U.S. agency securities
Amortized Cost
Amortized Cost, Due after 1 year through 5 years	7,850
Amortized Cost, Due after 5 years through 10 years	29,997
Amortized Cost, Due after 10 years	49,614
Amortized Cost	87,461	90,459
Fair Value
Fair Value, Due after 1 year through 5 years	7,729
Fair Value, Due after 5 years through 10 years	27,174
Fair Value, Due after 10 years	40,231
Fair Value	75,134	75,946
U.S. agency residential mortgage-backed securities
Amortized Cost
Amortized Cost, Due after 5 years through 10 years	3,325
Amortized Cost, Due after 10 years	261,763
Fair Value
Fair Value, Due after 5 years through 10 years	3,209
Fair Value, Due after 10 years	224,408
Fair Value	227,617	226,925
Mortgage-backed securities
Amortized Cost
Amortized Cost, Due after 1 year through 5 years	2,648
Amortized Cost, Due after 5 years through 10 years	898
Amortized Cost, Due after 10 years	58,399
Amortized Cost	61,945	62,882
Fair Value
Fair Value, Due after 1 year through 5 years	2,452
Fair Value, Due after 5 years through 10 years	781
Fair Value, Due after 10 years	53,320
Fair Value	56,553	56,674
Municipal securities
Amortized Cost
Amortized Cost, Due after 1 year through 5 years	306
Amortized Cost, Due after 5 years through 10 years	309
Amortized Cost, Due after 10 years	2,611
Amortized Cost	3,226	3,236
Fair Value
Fair Value, Due after 1 year through 5 years	282
Fair Value, Due after 5 years through 10 years	275
Fair Value, Due after 10 years	1,903
Fair Value	2,460	2,539
Other asset-backed securities
Amortized Cost
Amortized Cost, Due after 1 year through 5 years	116
Amortized Cost, Due after 5 years through 10 years	11,253
Amortized Cost, Due after 10 years	7,902
Amortized Cost	19,271	21,364
Fair Value
Fair Value, Due after 1 year through 5 years	115
Fair Value, Due after 5 years through 10 years	11,263
Fair Value, Due after 10 years	7,493
Fair Value	$ 18,871	$ 20,792

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
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-Publisher FASB
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Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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