Credit Loss Reserves - Summarizes Changes in Credit Loss Reserves by Product/Class and Related Receivable Balance by Product - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2015		Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Initial lower of amortized cost or fair value adjustment		$ 220		$ 42	$ (220)		$ 102
Write-offs	[1]	1,898	[2]	195	2,045	[2]	506
Excludes Credit loss reserves for TDR Loans that are carried at the lower of amortized cost or fair value		10		34	10		34
TDR [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Excludes TDR loans that are carried at the lower of amortized cost or fair value		256		544	256		544
Real Estate Secured Receivable Portfolio [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Write-offs		1,578		$ 18	1,593		$ 38
Mortgage Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Release of provision associated with a correction to the reserve calculation for a segment of the portfolio					19
First and Second Mortgage [Member] | Fair Value [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Initial lower of amortized cost or fair value adjustment		$ 220			$ 220

[1] 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 six months ended June 30, 2015 and 2014 and, accordingly, we recognized the existing credit loss reserves on these receivables as additional charge-off totaling $1,578 million and $1,593 million during the three and six months ended June 30, 2015 compared with $18 million and $38 million during the three and six months ended June 30, 2014, respectively.

[2] The provision for credit losses and charge-offs for real estate secured receivables during the three and six months ended June 30, 2015 includes $220 million related to the lower of amortized cost or fair value adjustment attributable to credit factors for receivables transferred to held for sale in June 2015. See Note 5, "Receivables Held for Sale," for additional information. The provision for credit losses for real estate secured receivables during the six months ended June 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.