Mortgage Loans Held for Sale and Investment - Mortgage Loans Held for Sale (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale – UPB	$ 1,639
Mark-to-market adjustment	42
Total mortgage loans held for sale	1,681
UPB	46
Fair Value	$ 43
Predecessor
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale – UPB		$ 1,837
Mark-to-market adjustment		54
Total mortgage loans held for sale		1,891
UPB		66
Fair Value		$ 64

Amount, after allowance for bad debt, of mortgage loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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