Sale of Accounts Receivable (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Accounts Receivable Securitization Programs [Line Items]
Maximum amount of facility provided under accounts receivable securitization program	$ 1,600,000,000		$ 1,600,000,000
Proceeds from Sale and Collection of Receivables			14,700,000,000	18,900,000,000
Collections applied to deferred consideration			13,600,000,000	18,900,000,000
Cash payments received in exchange for the transfer of accounts receivable	600,000,000		600,000,000		1,900,000,000
Proceeds from transfer of receivables	400,000,000		400,000,000		1,100,000,000
Deferred receivables consideration	216,000,000		216,000,000		757,000,000
Loss on transfer of accounts receivables to purchasers	1,000,000	1,000,000	2,000,000	2,000,000
Program [Member]
Accounts Receivable Securitization Programs [Line Items]
Maximum amount of facility provided under accounts receivable securitization program	1,200,000,000		1,200,000,000
Second Program [Member]
Accounts Receivable Securitization Programs [Line Items]
Maximum amount of facility provided under accounts receivable securitization program	$ 400,000,000		$ 400,000,000