Derivatives - Credit Value Adjustment Recorded Related to Notional Amount of Derivatives Outstanding (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Credit value adjustment	$ (2,792)	$ (272)
Not Designated as Hedging Instrument [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	631,446	587,275
Not Designated as Hedging Instrument [Member] \| Interest Rate Cap [Member]
Derivative [Line Items]
Derivative, Notional Amount	66,527	87,188
Not Designated as Hedging Instrument [Member] \| Interest Rate Collar [Member]
Derivative [Line Items]
Derivative, Notional Amount	35,354	35,354
Not Designated as Hedging Instrument [Member] \| Credit Default Swap, Buying Protection [Member]
Derivative [Line Items]
Derivative, Notional Amount	220,280	164,632
Not Designated as Hedging Instrument [Member] \| Credit Default Swap, Selling Protection [Member]
Derivative [Line Items]
Derivative, Sold Protection Notional Amount	(78,522)	(69,011)
Not Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount	47,874	25,460
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Fair value adjustment	(3,665)	801
Designated as Hedging Instrument [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	70,000	70,000
Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivative [Line Items]
Derivative, Notional Amount	65,000	30,000
Fair value adjustment	(483)	(63)
Designated as Hedging Instrument [Member] \| Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount	2,119	4,789
Fair value adjustment	$ (5)	$ (41)

Derivative, Sold Protection Notional Amount

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of credit risk valuation adjustment to derivative liabilities to properly reflect the credit quality of the entity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4CC
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

+ Details

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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.

+ Details

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Period Type:	duration

- Definition

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
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

+ Details

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- Details

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- Details

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