Financial Instruments (Cash flow hedges) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Summary Of Cash Flow Hedge Activity [Line Items]
Pre-tax gain (loss) included in AOCI related to cash flow hedges of forecasted transactions			$ (164)
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			$ 214
Maximum term of hedged forecasted transactions			P17Y	P18Y
Hedge ineffectiveness gain (loss)	$ (53)	$ (49)	$ (85)	$ (65)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	373	(160)	(668)	26
Gain (loss) reclassified from AOCI into earnings	406	(204)	(586)	(139)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Interest Rate Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	(7)	(12)	(10)	(9)
Gain (loss) reclassified from AOCI into earnings	(22)	(60)	(61)	(129)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Foreign Exchange Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	380	(148)	(658)	35
Gain (loss) reclassified from AOCI into earnings	428	(144)	(525)	(10)
Net Investment Hedge [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Hedge ineffectiveness gain (loss)			(56)	(311)
Net Investment Hedge [Member] | Foreign Exchange Contract [Member]
Summary Of Cash Flow Hedge Activity [Line Items]
Gain (loss) recognized in AOCI	(1,551)	435	3,438	(598)
Gain (loss) reclassified from AOCI into earnings	$ (196)	$ 0	$ 589	$ 10