Sale of Accounts Receivable (Narrative) (Details) (USD $)	6 Months Ended	12 Months Ended
	Dec. 31, 2012	Jun. 30, 2012
Sale of Accounts Receivable [Abstract]
Maximum amount provided under accounts receivable securitization facility excluded in lines of credit	$ 1,000,000,000
Receivables sold under securitization facility derecognized during the period	1,900,000,000
Cash payments received in exchange for the transfer of accounts receivable	1,000,000,000
Deferred consideration	900,000,000	629,000,000
Proceeds received in cash from transfers of receivables to purchasers	21,900,000,000	8,900,000,000
Cash collections on deferred consideration	21,900,000,000	8,900,000,000
Loss on transfer of accounts receivables to purchasers	$ 4,000,000	$ 4,000,000