Securities - Contractual Maturity Information for Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Investments Debt And Equity Securities [Abstract]
Due in 1 year or less, Amortized Cost	$ 104,769
Due after 1 year through 5 years, Amortized Cost	332,566
Due after 5 years through 10 years, Amortized Cost	826,088
Due after 10 years, Amortized Cost	1,671,881
Total, Amortized cost	2,935,304
Mortgage-backed securities, Amortized cost	2,691,133
Amortized Cost	5,626,437	$ 5,691,868
Due in 1 year or less, Fair Value	103,830
Due after 1 year through 5 years, Fair Value	323,313
Due after 5 years through 10 years, Fair Value	784,857
Due after 10 years, Fair Value	1,526,525
Total, Fair value	2,738,525
Mortgage-backed securities, Fair value	2,286,613
Total securities held to maturity, Fair value	$ 5,025,138	$ 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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