Derivatives - Credit Value Adjustment Recorded Related to Notional Amount of Derivatives Outstanding (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Credit value adjustment	$ (272)	$ (3)
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	587,275	411,645
Not Designated as Hedging Instrument [Member] | Interest Rate Cap [Member]
Derivative [Line Items]
Derivative, Notional Amount	87,188	36,111
Not Designated as Hedging Instrument [Member] | Interest Rate Collar [Member]
Derivative [Line Items]
Derivative, Notional Amount	35,354	0
Not Designated as Hedging Instrument [Member] | Credit Default Swap, Buying Protection [Member]
Derivative [Line Items]
Derivative, Notional Amount	164,632	162,139
Not Designated as Hedging Instrument [Member] | Credit Default Swap, Selling Protection [Member]
Derivative [Line Items]
Derivative, Sold Protection Notional Amount	(69,011)	(59,315)
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount	25,460	9,900
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Fair value adjustment	801	(133)
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	70,000	65,000
Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivative [Line Items]
Derivative, Notional Amount	30,000	15,000
Fair value adjustment	(63)	(170)
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount	4,789	1,927
Fair value adjustment	$ (41)	$ (6)