Securities - Contractual Maturity Information for Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Investments Debt And Equity Securities [Abstract]
Due in 1 year or less, Amortized Cost	$ 94,047
Due after 1 year through 5 years, Amortized Cost	315,932
Due after 5 years through 10 years, Amortized Cost	841,919
Due after 10 years, Amortized Cost	1,704,005
Total, Amortized cost	2,955,903
Mortgage-backed securities, Amortized cost	2,854,688
Amortized Cost	5,810,591	$ 5,861,599
Due in 1 year or less, Fair Value	93,373
Due after 1 year through 5 years, Fair Value	305,894
Due after 5 years through 10 years, Fair Value	805,379
Due after 10 years, Fair Value	1,572,173
Total, Fair value	2,776,819
Mortgage-backed securities, Fair value	2,457,417
Total securities held to maturity, Fair value	$ 5,234,236	$ 5,280,659

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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