Derivatives - Credit Value Adjustment Recorded Related to Notional Amount of Derivatives Outstanding (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	$ (1,422)	$ (2,792)
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	704,383	631,446
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	(2,890)	(3,665)
Derivative, Notional Amount	420,000	70,000
Interest Rate Cap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	66,137	66,527
interest Rate Collar [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	35,354	35,354
Credit Default Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	214,736	220,280
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	38,509	47,874
Forward Contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	182	(483)
Derivative, Notional Amount	36,000	65,000
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	17	(5)
Derivative, Notional Amount	2,589	2,119
Short [Member] | Credit Default Swap, Selling Protection [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 90,539	$ 78,522