Derivative Financial Instruments - Schedule of Effect of Derivative Instruments on the Consolidated Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income on Derivative	$ (246)	$ 944	$ 7,557	$ 552
Gain (Loss) Reclassified from AOCI into Income	1,670	6	2,101	391
Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	7,109	711	11,443	1,699
Interest rate contracts \| Interest income/(expense)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income on Derivative	(246)	944	7,557	552
Gain (Loss) Reclassified from AOCI into Income	1,670	6	2,101	391
Interest rate contracts \| Interest income/(expense) \| Fair Value Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	730	6,361	9,972	12,914
Interest rate contracts \| Other income/(expense) \| Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	(122)	(94)	(588)	(131)
Mortgage contracts \| Mortgage banking revenue \| Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	7,236	819	12,055	1,841
Foreign currency contracts \| Other income/(expense) \| Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivative	(5)	(14)	(24)	(11)
Fixed-rate debt \| Interest income/(expense) \| Fair Value Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Related Hedged Items	$ (789)	$ (6,352)	$ (10,016)	$ (12,900)

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

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Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

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Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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