Investment Securities (Securities Held to Maturity by Contractual Maturity) (Detail) $ in Thousands	Jun. 30, 2023 USD ($)
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, amortized cost	$ 25,283
Due after one year through five years, amortized cost	169,684
Due after five years through ten years, amortized cost	153,491
Due after ten years, amortized cost	30,461
Amortized cost	378,919
Due in one year or less, fair value	25,199
Due after one year through five years, fair value	166,605
Due after five years through ten years, fair value	148,121
Due after ten years, fair value	25,104
Fair value	$ 365,029

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