Receivables - TDR Loans (Detail) - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Unpaid principal balance subject to reduction		$ 683	$ 549
TDR Loans held for investment, recorded at the lower of amortized cost or FV less cost to sell		256	517
Real Estate Secured [Member] | Receivables Held For Sale [Member]
Financing Receivable, Modifications [Line Items]
TDR Loans	[1],[2],[3]	7,433	650
First lien [Member]
Financing Receivable, Modifications [Line Items]
TDR Loans	[1],[2],[4]	1,043	9,630
Credit loss reserves for TDR loans	[5]	139	1,738
Unpaid balance of TDR loans		1,187	9,931
Second lien [Member]
Financing Receivable, Modifications [Line Items]
TDR Loans	[1],[2],[4]	698	915
Credit loss reserves for TDR loans	[5]	159	244
Unpaid balance of TDR loans		792	1,050
Receivables Held For Sale [Member] | Real Estate Secured [Member]
Financing Receivable, Modifications [Line Items]
Unpaid balance of TDR loans		9,358	1,004
Real estate secured [Member]
Financing Receivable, Modifications [Line Items]
TDR Loans	[1],[2]	9,174	11,195
Credit loss reserves for TDR loans	[3],[5]	298	1,982
Unpaid balance of TDR loans		$ 11,337	$ 11,985

[1] TDR Loans are considered to be impaired loans regardless of accrual status.

[2] The following table reflects the unpaid principal balance of TDR Loans. Real Estate Secured: First lien $1,187 million and $9,931 million at June 30, 2015 and December 31, 2014, respectively; Second lien $792 million and $1,050 million at June 30, 2015 and December 31, 2014, respectively; Real estate secured receivables held for sale $9,358 million and $1,004 million at June 30, 2015 and December 31, 2014, respectively; Total real estate secured $11,337 million and $11,985 million at June 30, 2015 and December 31, 2014, respectively. At June 30, 2015 and December 31, 2014, the unpaid principal balances reflected above include $683 million and $549 million, respectively, which has received a reduction in the unpaid principal balance as part of an account management action.

[3] There are no credit loss reserves associated with receivables classified as held for sale as they are carried at the lower of amortized cost or fair value.

[4] At June 30, 2015 and December 31, 2014, TDR Loans held for investment totaling $256 million and $517 million, respectively, are recorded at the lower of amortized cost or fair value of the collateral less cost to sell.

[5] Included in credit loss reserves.