Derivative Financial Instruments - Effect of Derivative Instruments on Consolidated Statement of Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net, Total	$ (965)	$ (25,299)	$ (9,885)	$ (9,425)
Fair Value Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net, Total	(1,020)	(20,430)	(7,925)	(5,671)
Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net, Total	55	(4,869)	(1,960)	(3,754)
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Amount of Gains (Losses) Recognized in Net Interest Income on Derivative Instruments	0	105	0	105
Derivatives Not Designated as Hedging Instruments [Member] \| Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Amount of Gains (Losses) Recognized in Net Interest Income on Derivative Instruments	$ 0	$ 105	$ 0	$ 105
Derivative, Gain, Statement of Income or Comprehensive Income [Extensible Enumeration]	Noninterest Income	Noninterest Income	Noninterest Income	Noninterest Income
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net, Total	$ 1,467	$ 5,178	$ 4,105	$ 14,058
Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net, Total	$ 1,299	$ 4,286	$ 3,607	$ 12,070
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net, Total	$ 168	$ 892	$ 498	$ 1,988
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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