Derivative Instruments and Hedging Activities - Additional Information (Detail) $ in Thousands	6 Months Ended
Jun. 30, 2019 USD ($) derivative swap	Dec. 31, 2018 USD ($) derivative swap
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification adjustment from accumulated other comprehensive income	$ 4,500
Length of hedging exposure to variability in future cash flows (months)	60 months
Derivative, net liability position, aggregate fair value	$ 45,000
Minimum
Derivative Instruments, Gain (Loss) [Line Items]
Derivative expiration period	30 days
Maximum
Derivative Instruments, Gain (Loss) [Line Items]
Derivative expiration period	60 days
Not Designated as Hedging Instrument \| Residential mortgage loan commitments
Derivative Instruments, Gain (Loss) [Line Items]
Aggregate notional amount	$ 8,100	$ 3,600
Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gross amounts not offset in the consolidated balance sheet, Cash collateral pledged	$ 44,832	$ 702
Interest Rate Swaps \| Derivative Designated as Cash Flow Hedges \| Cash Flow Hedges
Derivative Instruments, Gain (Loss) [Line Items]
Number of outstanding interest rate derivatives (derivative) \| derivative	4	6
Aggregate notional amount	$ 725,000	$ 750,000
Interest Rate Swaps \| Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Aggregate notional amount	$ 1,200,000	$ 1,000,000
Number of interest rate swaps (swap) \| swap	116	98
Credit Contract \| Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Aggregate notional amount	$ 115,100	$ 94,900

Derivative, Length of Hedging Exposure to Variability in Future Cash Flows

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 13
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-Topic 815
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-Section 50
-Paragraph 3
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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- Definition

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.

+ References

No definition available.

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- Definition

The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80845-113994

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
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- Definition

Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

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

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