Financing Agreements - Long-term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2017		Dec. 31, 2016
Debt Instrument [Line Items]
Principal	$ 1,752		$ 1,670
Unamortized Debt Issue Costs	$ (20)		$ (21)
Cash Flow Hedging [Member]
Debt Instrument [Line Items]
Derivative, fixed interest rate	5.14%
Senior Notes Due September 2021 [Member]
Debt Instrument [Line Items]
Interest rate	5.375%		5.375%
Principal	$ 450		$ 450
Unamortized Debt Issue Costs	$ (5)		$ (5)
Senior Notes Due September 2023 [Member]
Debt Instrument [Line Items]
Interest rate	6.00%		6.00%
Principal	$ 300		$ 300
Unamortized Debt Issue Costs	$ (4)		$ (4)
Senior Notes Due December 2024 [Member]
Debt Instrument [Line Items]
Interest rate	5.50%		5.50%
Principal	$ 425		$ 425
Unamortized Debt Issue Costs	$ (5)		$ (6)
Senior Notes Due June 2026 [Member]
Debt Instrument [Line Items]
Interest rate	6.50%	[1]	6.50%
Principal	$ 375		$ 375
Unamortized Debt Issue Costs	$ (6)		(6)
Senior Notes Due June 2026 [Member] | Cash Flow Hedging [Member]
Debt Instrument [Line Items]
Interest rate	6.50%
Other indebtedness [Member]
Debt Instrument [Line Items]
Principal	$ 202		120
Unamortized Debt Issue Costs

[1] In conjunction with the issuance of the June 2026 Notes we entered into two 10-year fixed-to-fixed cross-currency swaps which have the effect of economically converting the June 2026 Notes to euro-denominated debt at a fixed rate of 5.140%. See Note 13 for additional information.