Sale of Accounts Receivable (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Accounts Receivable Securitization Programs [Line Items]
Proceeds from Sale and Collection of Receivables			$ 23,700,000,000	$ 27,800,000,000
Collections applied to deferred consideration			22,400,000,000	27,800,000,000
Cash payments received in exchange for the transfer of accounts receivable	2,000,000,000		2,000,000,000		1,900,000,000
Proceeds from transfer of receivables	1,300,000,000		1,300,000,000		1,100,000,000
Deferred receivables consideration	695,000,000		695,000,000		757,000,000
Loss on transfer of accounts receivables to purchasers	2,000,000	1,000,000	4,000,000	3,000,000
Accounts Receivable Securitization Facility [Member]
Accounts Receivable Securitization Programs [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,600,000,000		1,600,000,000
Accounts Receivable Securitization Facility [Member] | Program [Member]
Accounts Receivable Securitization Programs [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,200,000,000		1,200,000,000
Accounts Receivable Securitization Facility [Member] | Second Program [Member]
Accounts Receivable Securitization Programs [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 400,000,000		$ 400,000,000