Other Assets and Liabilities - Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity, Past Due [Line Items]
Loan portfolio payments held by servicer	$ 81,261		$ 49,584
Debt securities held-to-maturity	79,955		86,638
CECL reserve	(4,119)	$ (5,122)	0
Debt securities held-to-maturity, net	75,836		86,638
Accrued interest receivable	60,792		66,649
Collateral deposited under derivative agreements	22,180		30,800
Prepaid taxes	376		376
Prepaid expenses	328		739
Derivative assets	327		1,079
Other	834		1,115
Total	$ 241,934		$ 236,980