Payables and Accrued Liabilities - (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounts Payable [Line Items]
Payables to servicing and subservicing investors	$ 494
Loans subject to repurchase from Ginnie Mae	266
MSR purchases payable including advances	182
Payable to GSEs and securitized trusts	105
Other liabilities	496
Total payables and accrued liabilities	$ 1,543
Predecessor
Accounts Payable [Line Items]
Payables to servicing and subservicing investors		$ 516
Loans subject to repurchase from Ginnie Mae		218
MSR purchases payable including advances		10
Payable to GSEs and securitized trusts		92
Other liabilities		403
Total payables and accrued liabilities		$ 1,239