Fair Value Measurements - Carrying and Estimated Fair Value (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Financial assets:
Cash	$ 197		$ 215
Interest bearing deposits with banks	1,371		1,140
Securities purchased under agreement to resell	2,160		920
Financial liabilities:
Commercial paper	0		4,026		3,157
Long-term debt carried at fair value	9,700		13,700
Long-term debt not carried at fair value	28,426		39,790
Level 1
Financial assets:
Cash	197
Interest bearing deposits with banks	0
Securities purchased under agreement to resell	0
Securities available-for-sale	80
Real estate secured:
Total real estate secured	0	[1]
Personal non-credit card	0	[1]
Loans and Leases Receivable, Gross, Consumer, Total	0	[1]
Receivables held for sale	0
Due from affiliates	0
Derivative financial assets	0
Financial liabilities:
Commercial paper	0
Due to affiliates carried at fair value	0
Due to Affiliate	0
Long-term debt carried at fair value	0
Long-term debt not carried at fair value	0
Derivative financial liabilities	0
Level 1 | First Mortgage [Member]
Real estate secured:
Total real estate secured	0	[1]
Level 1 | Second Mortgage [Member]
Real estate secured:
Total real estate secured	0	[1]
Level 2
Financial assets:
Cash	0
Interest bearing deposits with banks	1,371
Securities purchased under agreement to resell	2,160
Securities available-for-sale	0
Real estate secured:
Total real estate secured	0	[1]
Personal non-credit card	0	[1]
Loans and Leases Receivable, Gross, Consumer, Total	0	[1]
Receivables held for sale	0
Due from affiliates	105
Derivative financial assets	0
Financial liabilities:
Commercial paper	0
Due to affiliates carried at fair value	514
Due to Affiliate	8,654
Long-term debt carried at fair value	9,725
Long-term debt not carried at fair value	16,537
Derivative financial liabilities	22
Level 2 | First Mortgage [Member]
Real estate secured:
Total real estate secured	0	[1]
Level 2 | Second Mortgage [Member]
Real estate secured:
Total real estate secured	0	[1]
Level 3
Financial assets:
Cash	0
Interest bearing deposits with banks	0
Securities purchased under agreement to resell	0
Securities available-for-sale	0
Real estate secured:
Total real estate secured	20,699	[1]
Personal non-credit card	0	[1]
Loans and Leases Receivable, Gross, Consumer, Total	20,699	[1]
Receivables held for sale	0
Due from affiliates	0
Derivative financial assets	0
Financial liabilities:
Commercial paper	0
Due to affiliates carried at fair value	0
Due to Affiliate	0
Long-term debt carried at fair value	0
Long-term debt not carried at fair value	2,635
Derivative financial liabilities	0
Level 3 | First Mortgage [Member]
Real estate secured:
Total real estate secured	19,586	[1]
Level 3 | Second Mortgage [Member]
Real estate secured:
Total real estate secured	1,113	[1]
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Financial assets:
Cash	197		215
Interest bearing deposits with banks	1,371		1,140
Securities purchased under agreement to resell	2,160		920
Securities available-for-sale	80		188
Real estate secured:
Total real estate secured	29,241	[1]	38,788	[1]
Personal non-credit card	0	[1]	4,308	[1]
Loans and Leases Receivable, Gross, Consumer, Total	29,241	[1]	43,096	[1]
Receivables held for sale	6,203		0
Due from affiliates	105		124
Derivative financial assets	0		0
Financial liabilities:
Commercial paper	0		4,026
Due to affiliates carried at fair value	514		447
Due to Affiliate	8,575		7,815
Long-term debt carried at fair value	9,725		13,664
Long-term debt not carried at fair value	18,701		26,126
Derivative financial liabilities	22		26
Carrying (Reported) Amount, Fair Value Disclosure [Member] | First Mortgage [Member]
Real estate secured:
Total real estate secured	26,175	[1]	34,960	[1]
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Second Mortgage [Member]
Real estate secured:
Total real estate secured	3,066	[1]	3,828	[1]
Fair Value
Financial assets:
Cash	197		215
Interest bearing deposits with banks	1,371		1,140
Securities purchased under agreement to resell	2,160		920
Securities available-for-sale	80		188
Real estate secured:
Total real estate secured	20,699	[1]	25,548	[1]
Personal non-credit card	0	[1]	3,180	[1]
Loans and Leases Receivable, Gross, Consumer, Total	20,699	[1]	28,728	[1]
Receivables held for sale	6,203		0
Due from affiliates	105		124
Derivative financial assets	0		0
Financial liabilities:
Commercial paper	0		4,026
Due to affiliates carried at fair value	514		447
Due to Affiliate	8,654		7,514
Long-term debt carried at fair value	9,725		13,664
Long-term debt not carried at fair value	19,172		25,090
Derivative financial liabilities	22		26
Fair Value | First Mortgage [Member]
Real estate secured:
Total real estate secured	19,586	[1]	24,438	[1]
Fair Value | Second Mortgage [Member]
Real estate secured:
Total real estate secured	$ 1,113	[1]	$ 1,110	[1]

[1] The carrying amount of consumer receivables presented in the table above reflects the amortized cost of the receivable, including any accrued interest, less credit loss reserves.