Amount of assets pledged to secure a debt instrument.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Name:	us-gaap_DebtInstrumentCollateralAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Mortgage-Backed Debt - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Feb. 09, 2018
Mortgage-Backed Debt [Member] \| Residential Loans, Receivables, Real Estate Owned and Restricted Cash [Member]
Beneficial Interests And Related Collateral [Line Items]
Collateral pledged	$ 123,300
Fresh-Start Adjustments [Member]
Beneficial Interests And Related Collateral [Line Items]
Fresh start accounting, increase to mortgage-backed debt		$ 6,246