Credit Loss Reserves - Summarizes Changes in Credit Loss Reserves by Product/Class and Related Receivable Balance by Product (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Credit loss reserves at beginning of period		$ 254	$ 408	$ 311	$ 2,217
Provision for credit losses	[1]	572	18	621	237
Charge-offs	[1],[2]	(827)	(90)	(938)	(2,135)
Recoveries		1	5	6	22
Total net charge-offs		(826)	(85)	(932)	(2,113)
Credit loss reserves at end of period		0	341	0	341
Reserve components:
Collectively evaluated for impairment										$ 88
Individually evaluated for impairment	[3]									241
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell										12
Total credit loss reserves		254	408	311	2,217	$ 0		$ 311		341
Receivables held for investment:
Collectively evaluated for impairment										7,986
Individually evaluated for impairment	[3]									1,315
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell										328
Total receivables						0	[4],[5]	9,156	[4],[5]	9,629
First lien [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Credit loss reserves at beginning of period		102	200	137	1,898
Provision for credit losses	[1]	75	11	107	215
Charge-offs	[1],[2]	(178)	(63)	(247)	(1,979)
Recoveries		1	4	3	18
Total net charge-offs		(177)	(59)	(244)	(1,961)
Credit loss reserves at end of period		0	152	0	152
Reserve components:
Collectively evaluated for impairment										45
Individually evaluated for impairment	[3]									95
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell										12
Total credit loss reserves		102	200	137	1,898	0		137		152
Receivables held for investment:
Collectively evaluated for impairment										6,713
Individually evaluated for impairment	[3]									661
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell										301
Total receivables						0		7,302		7,675
Second lien [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Credit loss reserves at beginning of period		152	208	174	319
Provision for credit losses	[1]	497	7	514	22
Charge-offs	[1],[2]	(649)	(27)	(691)	(156)
Recoveries		0	1	3	4
Total net charge-offs		(649)	(26)	(688)	(152)
Credit loss reserves at end of period		0	189	0	189
Reserve components:
Collectively evaluated for impairment										43
Individually evaluated for impairment	[3]									146
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell										0
Total credit loss reserves		$ 152	$ 208	$ 174	$ 319	0		174		189
Receivables held for investment:
Collectively evaluated for impairment										1,273
Individually evaluated for impairment	[3]									654
Receivables carried at the lower of amortized cost or fair value of the collateral less cost to sell										27
Total receivables						$ 0		$ 1,854		$ 1,954

[1] The provision for credit losses and charge-offs for real estate secured receivables during the three and nine months ended September 30, 2016 include $557 million and $576 million, respectively, related to the lower of amortized cost or fair value adjustment attributable to credit factors for receivables transferred to held for sale. For the three and nine months ended September 30, 2015, the provision for credit losses and charge-offs included $12 million and $232 million, respectively, related to the lower of amortized cost or fair value adjustment attributable to credit factors for receivables transferred to held for sale. See Note 4, "Receivables Held for Sale," for additional information. During the nine months ended September 30, 2016, net charge-offs dollars were impacted by an out of period adjustment which decreased net charge-offs by $12 million in order to properly reflect charge-offs for receivables which received a partial forgiveness of principal as a result of an account modification in prior periods. The provision for credit losses for real estate secured receivables during the nine months ended September 30, 2015 was impacted by a release of approximately $19 million associated with a correction to our credit loss reserve calculation for a segment of our portfolio.

[2] For collateral dependent receivables that are transferred to held for sale, existing credit loss reserves at the time of transfer are recognized as a charge-off. We transferred to held for sale certain real estate secured receivables during the three and nine months ended September 30, 2016 and 2015 and, accordingly, we recognized the existing credit loss reserves on these receivables as additional charge-off totaling $244 million and $268 million during the three and nine months ended September 30, 2016, compared with $24 million and $1,617 million during the three and nine months ended September 30, 2015, respectively.

[3] These amounts represent TDR Loans for which we evaluate reserves using a discounted cash flow methodology. Each loan is individually identified as a TDR Loan and then grouped together with other TDR Loans with similar characteristics. The discounted cash flow impairment analysis is then applied to these groups of TDR Loans. The receivable balance above excludes TDR Loans held for investment that are carried at the lower of amortized cost or fair value of the collateral less cost to sell which totaled $249 million at September 30, 2015. The reserve component above excludes credit loss reserves totaling $10 million at September 30, 2015 for TDR Loans held for investment that are carried at the lower of amortized cost or fair value of the collateral less cost to sell. These receivables and credit loss reserves are reflected within receivables and credit loss reserves carried at the lower of amortized cost or fair value of the collateral less cost to sell in the table above.

[4] 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.

[5] 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.