Securities - Contractual Maturity Information for Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Due in 1 year or less, Amortized Cost	$ 232,274
Due after 1 year through 5 years, Amortized Cost	222,096
Due after 5 years through 10 years, Amortized Cost	802,704
Due after 10 years, Amortized Cost	1,659,855
Total, Amortized cost	2,916,929
Mortgage-backed securities, Amortized cost	2,632,661
Amortized Cost	5,549,590	$ 5,691,868
Due in 1 year or less, Fair Value	229,504
Due after 1 year through 5 years, Fair Value	216,413
Due after 5 years through 10 years, Fair Value	754,813
Due after 10 years, Fair Value	1,501,873
Total, Fair value	2,702,603
Mortgage-backed securities, Fair value	2,210,805
Total securities held to maturity, Fair value	$ 4,913,408	$ 5,183,367

Mortgage backed securities held to maturity amortized cost.

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Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as held-to-maturity.

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