Receivables Held for Investment, net - Aging Analysis of Past Due Loans (Detail) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total receivables		$ 0	[1],[2]	$ 9,156	[1],[2]	$ 9,629
Threshold period for current receivable		30 days
Real estate secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				558
Current	[3]			8,598
Total receivables	[4]			9,156
First lien [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				398
Current	[3]			6,904
Total receivables	[4]			7,302
Second lien [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				160
Current	[3]			1,694
Total receivables	[4]			1,854
Past Due, 30 - 89 days [Member] | Real estate secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				277
Past Due, 30 - 89 days [Member] | First lien [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				179
Past Due, 30 - 89 days [Member] | Second lien [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				98
Past Due, 90 plus days [Member] | Real estate secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				281
Past Due, 90 plus days [Member] | First lien [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				219
Past Due, 90 plus days [Member] | Second lien [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due receivables				$ 62

[1] At December 31, 2015, amount includes $1,654 million of closed-end real estate secured receivables which serve as collateral for secured financings previously issued under public trusts with an outstanding balance of $879 million at December 31, 2015. See Note 11, "Variable Interest Entities," for additional information.

[2] At December 31, 2015, amount includes deferred origination fees, net of costs, totaling $71 million and net unamortized premium on our receivables totaling $35 million.

[3] Receivables less than 30 days past due are presented as current.

[4] The receivable balances included in this table reflect the principal amount outstanding on the loan net of any charge-off recorded in accordance with our existing charge-off policies and include certain basis adjustments to the loan such as unearned income, unamortized deferred fees and costs on originated loans, purchase accounting fair value adjustments and premiums or discounts on purchased loans. However, these basis adjustments on the loans are excluded in other presentations of dollars of two-months-and-over contractual delinquency, nonaccrual receivable and nonperforming receivable account balances.