Financing Arrangements Notes Payable (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Short-term Debt [Line Items]
Total notes payable	$ 740	$ 569
Commercial paper
Short-term Debt [Line Items]
Total notes payable	645	387
Debt securitization
Short-term Debt [Line Items]
Total notes payable	0	35
Short-term borrowings to banks
Short-term Debt [Line Items]
Total notes payable	$ 95	$ 147