Credit Loss Reserves - Summarizes Changes in Credit Loss Reserves by Product/Class and Related Receivable Balance by Product - Additional Information (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Initial lower of amortized cost or fair value adjustment(2)		$ 234		$ 113
Write-offs	[1]	2,181	[2]	854	$ 1,521
Excludes Credit loss reserves for TDR Loans that are carried at the lower of amortized cost or fair value		10		25	38
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		250		517	604
Real Estate Secured Receivable Portfolio [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Write-offs		1,622		$ 58	$ 164
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(2)		$ 234

[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 years ended December 31, 2015, 2014 and 2013 and, accordingly, we recognized the existing credit loss reserves on these receivables as additional charge-off totaling $1,622 million during the year ended December 31, 2015 compared with $58 million and $164 million during the years ended December 31, 2014 and 2013, respectively.

[2] The provision for credit losses and charge-offs for real estate secured receivables during the year ended December 31, 2015 includes $234 million related to the lower of amortized cost or fair value adjustment attributable to credit factors for receivables transferred to held for sale. See Note 7, "Receivables Held for Sale," for additional information. The provision for credit losses for real estate secured receivables during the year ended December 31, 2015 was impacted by a release of approximately $19 million associated with an out of period adjustment to our credit loss reserve calculation for a segment of our portfolio.