Derivatives - Credit Value Adjustment Recorded Related to Notional Amount of Derivatives Outstanding (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	$ (91)	$ (3)
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	480,872	411,645
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	(124)	(133)
Derivative, Notional Amount	70,000	65,000
Interest Rate Cap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	87,401	36,111
interest Rate Collar [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	35,354	0
Credit Default Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	178,502	162,139
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	32,720	9,900
Forward Contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	(48)	(170)
Derivative, Notional Amount	47,000	15,000
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	50	(6)
Derivative, Notional Amount	4,874	1,927
Short [Member] | Credit Default Swap, Selling Protection [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 70,016	$ 59,315