Debt (Schedule of Balances Available for Borrowing) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Nov. 04, 2015	Nov. 03, 2015	Dec. 31, 2014	Sep. 30, 2014
Debt Instrument [Line Items]
AR transferred by Originators to the Transferor		$ 131
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Borrowings outstanding	[2]	350	[1]			$ 0
Letters of credit issued		0
Available for borrowing		550
Maximum borrowing base							$ 900
Proceeds from Lines of Credit		550
Repayments of Lines of Credit		200
Accounts Receivable Securitization Facility [Member]
Debt Instrument [Line Items]
Borrowings outstanding	[4]	55	[3]			$ 35
Letters of credit issued		59
Available for borrowing		0
Total borrowing base		114
Maximum borrowing base	[5]	120		$ 120	$ 135
Proceeds from Lines of Credit		35
Repayments of Lines of Credit		$ 15

[1] The Company borrowed $550 million and repaid $200 million during the year ended December 31, 2015. Borrowings were primarily used to fund repurchases of the Company's Common Stock.

[2] The weighted average interest rate was 1.8% and 0.0% as of December 31, 2015 and 2014, respectively.

[3] The Company borrowed $35 million and repaid $15 million during the year ended December 31, 2015.

[4] The weighted average interest rate was 0.8% and 0.7% as of December 31, 2015 and 2014, respectively.

[5] Outstanding accounts receivable transferred by the Originators to the Transferor was $131 million. On November 5, 2015, the Company reduced the maximum borrowing base from $135 million to $120 million.