Debt (Schedule of Accounts Receivable Securitization Facility)(Details) - Secured Debt [Member] - Accounts Receivable Securitization Facility [Member] $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($)
Debt Instrument [Line Items]
Borrowings outstanding	$ 0
Letters of credit issued	45
Available for borrowing	58
Total borrowing base	103
Maximum borrowing base	120	[1]
Outstanding accounts receivable transferred by the Originators to the Transferor	$ 173

[1] Outstanding accounts receivable transferred to the SPE was $173 million.