Carrying Value and Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Financial Assets:
Residential mortgage loans held-for-investment through consolidated securitization trusts, net for allowance of credit losses of $147 at June 30, 2020 and $175 at December 31, 2019(1)	[1]	$ 367,539	$ 458,348
Residential mortgage loans held-for-investment, Estimated Fair Value		371,022	461,606
Residential mortgage loans held-for-securitization, net of allowance for credit losses of $56 at June 30, 2020 and $0 at December 31, 2019		131,110	152,922
Residential mortgage loans held-for-securitization, Estimated Fair Value		122,364	154,442
Financial Liabilities:
Asset-backed securities issued by securitization trusts	[1]	358,854	448,987
Asset-backed securities issued by securitization trust, Estimated Fair Value		$ 361,652	$ 450,501

[1] The consolidated balance sheets include assets of consolidated variable interest entities, or VIEs, that can only be used to settle obligations and liabilities of the VIEs for which creditors do not have recourse to the Company. At June 30, 2020 and December 31, 2019, total assets of the consolidated VIEs were $369 million and $460 million (including accrued interest receivable of $1.3 million and $1.5 million), respectively (which is recorded above in the line item entitled “Interest receivable”), and total liabilities were $360 million and $450 million (including accrued interest payable of $1.2 million and $1.4 million), respectively (which is recorded in the line item above entitled “Accrued interest payable”). Please refer to Note 5, “Variable Interest Entities,” for further discussion.