Derivative Instruments and Other Financial Instruments Used For Hedging (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Derivative notional amount	$ 59,402	$ 53,628
Asset Derivatives, Fair Value	1,466	1,350
Liability Derivatives, Fair Value	1,346	1,308
Derivatives not designated as hedging instruments [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Derivative notional amount, Hedging instruments	48,902	46,228
Asset Derivatives, Fair Value	1,441	1,347
Liability Derivatives, Fair Value	1,346	1,298
Interest rate contracts [Member] | Derivatives designated as hedging instruments [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Derivative notional amount	10,500	7,400
Interest rate contracts [Member] | Derivatives designated as hedging instruments [Member] | Other assets [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Asset Derivatives, Fair Value	25	3
Interest rate contracts [Member] | Derivatives designated as hedging instruments [Member] | Other liabilities [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Liability Derivatives, Fair Value		10
Interest rate contracts [Member] | Derivatives not designated as hedging instruments [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Derivative notional amount, Hedging instruments	34,574	33,903
Interest rate contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account assets [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Asset Derivatives, Fair Value	997	922
Interest rate contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account liabilities [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Liability Derivatives, Fair Value	940	869
Commodity contracts [Member] | Derivatives not designated as hedging instruments [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Derivative notional amount, Hedging instruments	5,929	5,136
Commodity contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account assets [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Asset Derivatives, Fair Value	249	250
Commodity contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account liabilities [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Liability Derivatives, Fair Value	212	247
Foreign exchange contracts [Member] | Derivatives not designated as hedging instruments [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Derivative notional amount, Hedging instruments	4,985	4,152
Foreign exchange contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account assets [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Asset Derivatives, Fair Value	103	88
Foreign exchange contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account liabilities [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Liability Derivatives, Fair Value	105	95
Equity contracts [Member] | Derivatives not designated as hedging instruments [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Derivative notional amount, Hedging instruments	3,379	3,037
Equity contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account assets [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Asset Derivatives, Fair Value	89	87
Equity contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account liabilities [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Liability Derivatives, Fair Value	89	87
Credit Contracts [Member] | Derivatives not designated as hedging instruments [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Derivative notional amount, Hedging instruments	35
Credit Contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account assets [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Asset Derivatives, Fair Value	3
Credit Contracts [Member] | Derivatives not designated as hedging instruments [Member] | Trading account liabilities [Member]
Location and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheet
Liability Derivatives, Fair Value