Equity Activity: (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Accumulated Other Comprehensive Income (Loss) Net of Tax
Balance at the Beginning of the Period	$ (25,759)	$ (21,885)
Other comprehensive income before reclassifications	(245)	430
Amount reclassified from accumulated other comprehensive income	539	341
Total change for the period	293	770	[1]
Balance at the End of the Period	(25,466)	(21,115)
Net Unrealized Gains/(Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) Net of Tax
Balance at the Beginning of the Period	(90)	71
Other comprehensive income before reclassifications	232	21
Amount reclassified from accumulated other comprehensive income	(35)	(17)
Total change for the period	197	4
Balance at the End of the Period	107	75
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) Net of Tax
Balance at the Beginning of the Period	1,733	1,767
Other comprehensive income before reclassifications	(489)	398
Amount reclassified from accumulated other comprehensive income	0	0
Total change for the period	(489)	398
Balance at the End of the Period	1,243	2,165
Net Change Retirement-Related Benefit Plans
Accumulated Other Comprehensive Income (Loss) Net of Tax
Balance at the Beginning of the Period	(27,406)	(23,737)
Other comprehensive income before reclassifications	12	(4)
Amount reclassified from accumulated other comprehensive income	574	366
Total change for the period	586	363
Balance at the End of the Period	(26,820)	(23,374)
Net Unrealized Gains/(Losses) on Available-For-Sale Securities
Accumulated Other Comprehensive Income (Loss) Net of Tax
Balance at the Beginning of the Period	4	13
Other comprehensive income before reclassifications	(1)	15
Amount reclassified from accumulated other comprehensive income	0	(8)
Total change for the period	0	6
Balance at the End of the Period	$ 4	$ 19

[1] Amounts may not add due to rounding.