Debt (Schedule of Accounts Receivable Securitization Facility) (Details) - Accounts Receivable Securitization Facility [Member] - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Borrowings outstanding	[1]	$ 77	$ 77
Secured Debt [Member]
Debt Instrument [Line Items]
Borrowings outstanding		77
Letters of credit issued		29
Available for borrowing		5
Total borrowing base		111
Maximum borrowing base	[2]	120
Outstanding accounts receivable transferred by the Originators to the Transferor		$ 188

[1] The weighted average interest rate was 3.3% and 3.1% as of June 30, 2019 and December 31, 2018, respectively.

[2] Outstanding accounts receivable transferred to the SPE was $188 million.