Financial Instruments (Cash flow hedges) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Cash Flow Hedge [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	$ (160)	$ 292	$ 26	$ 247
Gain (loss) reclassified from AOCI into earnings	(204)	72	(139)	(75)
Pre-tax gain (loss) included in AOCI related to cash flow hedges of forecasted transactions			(142)
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			173
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	insignificant gains and losses	insignificant gains and losses
Maximum term of hedged forecasted transactions			18	19
Cash Flow Hedge [Member] | Interest Rate Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	(12)	20	(9)	9
Gain (loss) reclassified from AOCI into earnings	(60)	(92)	(129)	(194)
Cash Flow Hedge [Member] | Foreign Exchange Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	(148)	272	35	238
Gain (loss) reclassified from AOCI into earnings	(144)	164	(10)	119
Net Investment Hedge [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Hedge ineffectiveness gain (loss)	(169)	(187)	(311)	(353)
Net Investment Hedge [Member] | Foreign Exchange Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	435	412	(598)	2,517
Gain (loss) reclassified from AOCI into earnings	0	15	10	(109)
Fair Value Hedges [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Hedge ineffectiveness gain (loss)	$ (49)	$ 14	$ (65)	$ (15)