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Allowance for Credit Losses - Schedule of Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses and unfunded lending-related commitments losses	$ 454,191	$ 457,063	$ 436,603	$ 435,714	$ 437,069	$ 427,265
Allowance for held-to-maturity securities losses	395		457	479
Allowance for credit losses	454,586		437,060	436,193
Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses and unfunded lending-related commitments losses	386,622		364,017	360,279
Unfunded lending-related commitments
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses and unfunded lending-related commitments losses	67,569		72,586	75,435
Loans and unfunded lending-related commitments
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for loan losses and unfunded lending-related commitments losses	$ 454,191		$ 436,603	$ 435,714