Shareholders' Equity (Details 2) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (3,134)
Other comprehensive (loss) income before reclassifications, net	(376)
Amounts reclassified from accumulated other comprehensive loss:
Amounts reclassified from accumulated other comprehensive loss	101
Tax benefit	(44)
Amounts reclassified from accumulated other comprehensive loss, net	57
Net current period other comprehensive (loss) income	(319)
Ending balance	(3,453)
Change in Fair Value of Financial Instruments [Member]
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(17)	[1]
Other comprehensive (loss) income before reclassifications, net	(7)	[1]
Amounts reclassified from accumulated other comprehensive loss:
Amounts reclassified from accumulated other comprehensive loss	13	[1]
Tax benefit	(17)	[1]
Amounts reclassified from accumulated other comprehensive loss, net	(4)	[1]
Net current period other comprehensive (loss) income	(11)	[1]
Ending balance	(28)	[1]
Foreign Currency Translation Adjustments [Member]
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(335)
Other comprehensive (loss) income before reclassifications, net	(370)
Amounts reclassified from accumulated other comprehensive loss:
Amounts reclassified from accumulated other comprehensive loss	0
Tax benefit	0
Amounts reclassified from accumulated other comprehensive loss, net	0
Net current period other comprehensive (loss) income	(370)
Ending balance	(705)
Post-Retirement Benefit Obligation [Member]
Changes in Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(2,782)	[2]
Other comprehensive (loss) income before reclassifications, net	1	[2]
Amounts reclassified from accumulated other comprehensive loss:
Amounts reclassified from accumulated other comprehensive loss	88	[2]
Tax benefit	(27)	[2]
Amounts reclassified from accumulated other comprehensive loss, net	61	[2]
Net current period other comprehensive (loss) income	62	[2]
Ending balance	$ (2,720)	[2]

[1] Reclassifications from this category included in Accumulated other comprehensive loss are recorded in Other income.

[2] Reclassifications from this category included in Accumulated other comprehensive loss are recorded in Compensation and benefits.