Financial Instruments (Cash flow hedges) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Cash Flow Hedge [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	$ 678	$ 888
Gain (loss) reclassified from AOCI into earnings	224	330
Pre-tax gain (loss) included in AOCI related to cash flow hedges of forecasted transactions	291
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	(241)
Gain Loss Related To Hedge Forecasted Transactions And Firm Commitments That Did Not Occur By End Of Originally Specified Period	insignificant gains and losses	insignificant gains and losses
Maximum term of hedged forecasted transactions	19	20
Hedge ineffectiveness gain (loss)	1	4
Cash Flow Hedge [Member] | Interest Rate Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	(26)	(158)
Gain (loss) reclassified from AOCI into earnings	(364)	(494)
Cash Flow Hedge [Member] | Foreign Exchange Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	704	1,046
Gain (loss) reclassified from AOCI into earnings	588	824
Net Investment Hedge [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Hedge ineffectiveness gain (loss)	(678)	(874)
Net Investment Hedge [Member] | Foreign Exchange Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	2,322	(2,905)
Gain (loss) reclassified from AOCI into earnings	(1,525)	27
Fair Value Hedges [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Hedge ineffectiveness gain (loss)	$ (74)	$ (303)