Indebtedness (Narrative) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Feb. 28, 2014 Multi-year revolving credit, expiring March 31, 2015 [Member]	Mar. 31, 2014 Multi-year revolving credit, expiring February 28, 2019 [Member]
Line of Credit Facility [Line Items]
Credit Facilities No Longer Available			$ 2,500,000,000
Line of Credit Facility, Amount Outstanding	0
Short-term borrowings, carrying value	3,284,000,000	2,400,000,000
Line of Credit Facility, Maximum Borrowing Capacity	$ 8,000,000,000			$ 2,500,000,000