Derivative Financial Instruments (Counterparty Credit Risk Narrative) (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Derivative instrument asset, Amount Offset	$ 285,297	$ 232,190
Maximum exposure	16,700
Debit (credit) valuation adjustment	7,500	$ 6,200
Cash and Due from Banks
Derivative [Line Items]
Derivative, Collateral, Right to Reclaim Cash	290,300
Valuation, Market Approach
Derivative [Line Items]
Maximum exposure	112,000
CME
Derivative [Line Items]
Derivative instrument asset, Amount Offset	$ 2,300