Investment Securities - Summary Of Debt Securities Held-to Maturity - Contractual Maturities, Credit Quality and Other Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Amortized Cost
Maturing within 1 year	$ 2,889
After 1 year through 5 years	163,206
After 5 through 10 years	240,712
After 10 years	7,891,229
Amortized Cost	8,298,036	$ 8,444,362
Fair Value
Maturing within 1 year	2,890
After 1 year through 5 years	155,882
After 5 through 10 years	232,099
After 10 years	7,013,853
Fair Value	$ 7,404,724	$ 7,453,123

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

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