Receivables Held for Sale - Additional Information (Detail) $ in Millions			1 Months Ended		3 Months Ended		12 Months Ended
		Apr. 02, 2013 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2013 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)		Dec. 31, 2013 USD ($)		Sep. 01, 2013 employee
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aggregate unpaid balance							$ 11,796	$ 1,390
Aggregate carrying value			$ 11,399		$ 1,587		12,183	1,080
Initial lower of amortized cost or fair value adjustment(2)							234	113
Aggregate unpaid balance of real estate secured receivables					$ 1,986		2,591
Proceeds from sale of real estate secured receivables							2,022	2,242		$ 6,095
Aggregate carrying value of real estate secured receivables							1,995
Gain (loss) on sale of real estate secured receivables							12
Provision for Credit Losses [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Initial lower of amortized cost or fair value adjustment(2)	[1]						234
Other Revenue [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Initial lower of amortized cost or fair value adjustment(2)							0	113	[2]	212	[2]
Subsequent to initial transfer to held for sale							130	(314)		(748)
Fair Value [Member] | Provision for Credit Losses [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Initial lower of amortized cost or fair value adjustment(2)	[1]						234
Fair Value [Member] | Other Revenue [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Initial lower of amortized cost or fair value adjustment(2)							0	113	[2]	212	[2]
Subsequent to initial transfer to held for sale							$ 129	(322)		(686)
First Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Threshold, days past due to initiate sale activities for first lien real estate secured receivables							180 days
Consumer Loan Excluding Credit Card [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aggregate unpaid balance				$ 3,760
Proceeds from Sale of Loans Held-for-sale		$ 2,964
Gain (Loss) on Sales of Loans, Net						$ (11)
Aggregate carrying value				$ 2,947
Number of Employees Transferred to Purchaser | employee												200
Cash Flows Between Transferor and Transferee, Servicing Fees										28
First Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aggregate unpaid balance										3,612
Aggregate carrying value										2,506
Third-Party Investor [Member] | First Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Aggregate unpaid balance								2,927		5,685
Aggregate carrying value								2,152		3,127
Proceeds from Sale of Loans Held-for-sale								2,242		3,131
Gain (Loss) on Sales of Loans, Net								$ 63		$ (89)

[1] The portion of the initial lower of amortized cost or fair value adjustment attributable to credit factors was recorded as provision for credit losses in the consolidated statement of income (loss). This portion of the initial lower of amortized cost or fair value adjustment was attributed to credit factors as there was no objective, verifiable evidence to indicate non-credit factors were associated with the decline in fair value.

[2] The portion of the initial lower of amortized cost or fair value adjustment which reflects the impact on value caused by current marketplace conditions including changes in interest rates was recorded as a component of total other revenues in the consolidated statement income (loss).