Derivative Instruments and Hedging Activities (Fair Value of OTC Derivatives in a Gain Position) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Fair value of OTC derivatives in a gain position	$ 23,865	[1]	$ 35,049	[1]
AAA
Fair value of OTC derivatives in a gain position	3,088	[1],[2]	6,389	[1],[2]
AA
Fair value of OTC derivatives in a gain position	4,428	[1],[2]	7,048	[1],[2]
A
Fair value of OTC derivatives in a gain position	7,638	[1],[2]	7,117	[1],[2]
BBB
Fair value of OTC derivatives in a gain position	5,764	[1],[2]	10,337	[1],[2]
Non-investment Grade
Fair value of OTC derivatives in a gain position	2,947	[1],[2]	4,158	[1],[2]
Less than 1 Year
Fair value of OTC derivatives in a gain position	13,885	[1]	21,031	[1]
Less than 1 Year | AAA
Fair value of OTC derivatives in a gain position	353	[1],[2]	621	[1],[2]
Less than 1 Year | AA
Fair value of OTC derivatives in a gain position	2,125	[1],[2]	5,578	[1],[2]
Less than 1 Year | A
Fair value of OTC derivatives in a gain position	6,643	[1],[2]	7,576	[1],[2]
Less than 1 Year | BBB
Fair value of OTC derivatives in a gain position	2,673	[1],[2]	4,437	[1],[2]
Less than 1 Year | Non-investment Grade
Fair value of OTC derivatives in a gain position	2,091	[1],[2]	2,819	[1],[2]
1 - 3 Years
Fair value of OTC derivatives in a gain position	20,607	[1]	22,097	[1]
1 - 3 Years | AAA
Fair value of OTC derivatives in a gain position	551	[1],[2]	1,615	[1],[2]
1 - 3 Years | AA
Fair value of OTC derivatives in a gain position	3,635	[1],[2]	7,547	[1],[2]
1 - 3 Years | A
Fair value of OTC derivatives in a gain position	9,596	[1],[2]	5,538	[1],[2]
1 - 3 Years | BBB
Fair value of OTC derivatives in a gain position	3,970	[1],[2]	4,448	[1],[2]
1 - 3 Years | Non-investment Grade
Fair value of OTC derivatives in a gain position	2,855	[1],[2]	2,949	[1],[2]
3 - 5 Years
Fair value of OTC derivatives in a gain position	24,331	[1]	23,716	[1]
3 - 5 Years | AAA
Fair value of OTC derivatives in a gain position	1,299	[1],[2]	1,586	[1],[2]
3 - 5 Years | AA
Fair value of OTC derivatives in a gain position	2,958	[1],[2]	5,972	[1],[2]
3 - 5 Years | A
Fair value of OTC derivatives in a gain position	14,228	[1],[2]	10,224	[1],[2]
3 - 5 Years | BBB
Fair value of OTC derivatives in a gain position	3,704	[1],[2]	3,231	[1],[2]
3 - 5 Years | Non-investment Grade
Fair value of OTC derivatives in a gain position	2,142	[1],[2]	2,703	[1],[2]
Over 5 Years
Fair value of OTC derivatives in a gain position	69,244	[1]	81,702	[1]
Over 5 Years | AAA
Fair value of OTC derivatives in a gain position	6,121	[1],[2]	10,375	[1],[2]
Over 5 Years | AA
Fair value of OTC derivatives in a gain position	10,270	[1],[2]	21,068	[1],[2]
Over 5 Years | A
Fair value of OTC derivatives in a gain position	29,729	[1],[2]	27,417	[1],[2]
Over 5 Years | BBB
Fair value of OTC derivatives in a gain position	18,586	[1],[2]	17,758	[1],[2]
Over 5 Years | Non-investment Grade
Fair value of OTC derivatives in a gain position	4,538	[1],[2]	5,084	[1],[2]
Cross-Maturity and Cash Collateral Netting
Fair value of OTC derivatives in a gain position	(96,511)	[1],[3]	(104,585)	[1],[3]
Cross-Maturity and Cash Collateral Netting | AAA
Fair value of OTC derivatives in a gain position	(4,851)	[1],[2],[3]	(7,513)	[1],[2],[3]
Cross-Maturity and Cash Collateral Netting | AA
Fair value of OTC derivatives in a gain position	(12,761)	[1],[2],[3]	(31,074)	[1],[2],[3]
Cross-Maturity and Cash Collateral Netting | A
Fair value of OTC derivatives in a gain position	(50,721)	[1],[2],[3]	(41,608)	[1],[2],[3]
Cross-Maturity and Cash Collateral Netting | BBB
Fair value of OTC derivatives in a gain position	(21,704)	[1],[2],[3]	(17,932)	[1],[2],[3]
Cross-Maturity and Cash Collateral Netting | Non-investment Grade
Fair value of OTC derivatives in a gain position	(6,474)	[1],[2],[3]	(6,458)	[1],[2],[3]
Net Exposure Post-Cash Collateral
Fair value of OTC derivatives in a gain position	31,556	[1]	43,961	[1]
Net Exposure Post-Cash Collateral | AAA
Fair value of OTC derivatives in a gain position	3,473	[1],[2]	6,684	[1],[2]
Net Exposure Post-Cash Collateral | AA
Fair value of OTC derivatives in a gain position	6,227	[1],[2]	9,091	[1],[2]
Net Exposure Post-Cash Collateral | A
Fair value of OTC derivatives in a gain position	9,475	[1],[2]	9,147	[1],[2]
Net Exposure Post-Cash Collateral | BBB
Fair value of OTC derivatives in a gain position	7,229	[1],[2]	11,942	[1],[2]
Net Exposure Post-Cash Collateral | Non-investment Grade
Fair value of OTC derivatives in a gain position	$ 5,152	[1],[2]	$ 7,097	[1],[2]

[1] Fair values shown represent the Company’s net exposure to counterparties related to the Company’s OTC derivative products. Amounts include centrally cleared derivatives. The table does not include listed derivatives and the effect of any related hedges utilized by the Company.

[2] Obligor credit ratings are determined by the Company’s Credit Risk Management Department.

[3] Amounts represent the netting of receivable balances with payable balances for the same counterparty across maturity categories. Receivable and payable balances with the same counterparty in the same maturity category are netted within such maturity category, where appropriate. Cash collateral received is netted on a counterparty basis, provided legal right of offset exists.