Indebtedness (Long-Term Debt) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Long term debt obligations	$ 22,815	$ 20,420
Long-term Debt, Current	1,256	2,781
Long-term Debt	21,559	17,639
US Dollar Notes [Member] | U.S. Dollar Notes [Member]
Debt Instrument [Line Items]
Long-term Debt	14,515	14,702
Due through	2043
Interest rate, minimum	0.323%
Interest rate, maximum	6.875%
Interest rate, average	4.198%
Foreign Currency Obligations [Member] | Euro Notes [Member]
Debt Instrument [Line Items]
Long-term Debt	6,905	3,724
Due through	2033
Interest rate, minimum	1.75%
Interest rate, maximum	5.875%
Interest rate, average	3.339%
Foreign Currency Obligations [Member] | Swiss Franc Notes [Member]
Debt Instrument [Line Items]
Long-term Debt	1,214	1,579
Due through	2021
Interest rate, minimum	0.875%
Interest rate, maximum	2.00%
Interest rate, average	1.24%
Foreign Currency Obligations [Member] | Other [Member]
Debt Instrument [Line Items]
Long term debt obligations	$ 181	$ 415
Due through	2024
Interest rate, average	3.744%