Fair Value Disclosures (Short-term and Long-term Borrowings) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Balance Sheet Captions
Short-term and long-term borrowing, fair value	$ 33,155	$ 33,539
Equity
Balance Sheet Captions
Short-term and long-term borrowing, fair value	17,054	17,253
Interest Rates
Balance Sheet Captions
Short-term and long-term borrowing, fair value	13,614	13,545
Credit and Foreign Exchange Contracts
Balance Sheet Captions
Short-term and long-term borrowing, fair value	1,947	2,105
Commodities
Balance Sheet Captions
Short-term and long-term borrowing, fair value	$ 540	$ 636