Derivatives and Hedging Activities - Additional Information (Detail)	6 Months Ended
Jun. 30, 2020 USD ($) Derivative	Dec. 31, 2019 USD ($) Derivative
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Termination value of derivatives in net liability position	$ 430,000
Collateral posted for derivative instruments	$ 345,000
Derivatives Designated as Hedging Instruments [Member] \| Cash Flow Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest rate hedging exposure to variability in future cash flows for forecasted transactions, maximum period	16 years 2 months 19 days
Interest Rate Swap [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Fair Value Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 5,200,000	$ 5,300,000
Number of interest rate swaps \| Derivative	1	1
Interest Rate Swap [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Cash Flow Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 51,500,000	$ 51,500,000
Number of interest rate swaps \| Derivative	2	2
Interest Rate Swap [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Cash Flow Hedging [Member] \| Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Reclassification from AOCI to interest	$ 1,300,000
Interest Rate Swap [Member] \| Derivatives not Designated as Hedging Instruments [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 2,100,000,000	$ 1,900,000,000
Number of interest rate swaps \| Derivative	156	142
Interest Rate Floor [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Cash Flow Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 750,000,000.0	$ 750,000,000.0
Number of interest rate swaps \| Derivative	1	1
Interest Rate Floor [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Cash Flow Hedging [Member] \| Reduction To Interest Income [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Reclassification from AOCI to interest	$ 5,100,000

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

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Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
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The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

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Maximum period the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of interest rate derivative instruments held by the entity at the reporting date.

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