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

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Amount, after tax and before reclassification, of gain (loss) from derivative instrument designated and qualifying as 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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Derivative Instruments and Hedging Activities - Effect of Derivative Financial Instruments on Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	$ (764)	$ 2,519	$ (355)	$ 2,647
Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income		2,519		2,647
Other Non-interest Income \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income		2,822		2,822
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	(800)	(303)	(400)	(175)
Interest Expense \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	(3,821)	3,006	(19,391)	5,055
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	(764)	(303)	(355)	(175)
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Earnings	55	1,284	373	1,653
Not Designated as Hedging Instrument \| Other Non-interest Income \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Earnings	(35)	1,139	63	1,472
Not Designated as Hedging Instrument \| Other Non-interest Income \| Credit Contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Earnings	85	156	228	119
Not Designated as Hedging Instrument \| Mortgage Banking Income \| Residential Mortgage Loan Commitments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Earnings	$ 5	$ (11)	$ 82	$ 62