Derivative Instruments and Hedging Activities - Effect of Derivative Financial Instruments on Net Income and Comprehensive 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]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	$ (2,718)	$ (4)	$ (4,196)	$ 409
Interest Expense \| Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	(4,685)	(10,435)	(25,031)	(15,570)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income	(2,718)	(4)	(4,196)	409
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Earnings	(4,322)	495	(5,331)	318
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	(5,563)	386	(6,578)	98
Not Designated as Hedging Instrument \| Other Non-interest Income \| Interest Rate Cap
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Earnings	0	0	0	0
Not Designated as Hedging Instrument \| Other Non-interest Income \| Credit Contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Income (Loss) Recognized in Earnings	1,405	41	1,274	144
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	$ (164)	$ 68	$ (27)	$ 76

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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5618551-113959

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
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-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e689-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
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-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624171-113959

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