Short-term Borrowings and Current Portion of Long-term Debt (Schedule of Short-term Debt) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended
	May 02, 2013	Dec. 31, 2014	Dec. 31, 2013
Short-term Debt [Line Items]
Total short-term borrowings		$ 677	$ 1,580
Current portion of long-term debt		50	73
Short-term borrowings and current portion of long-term debt		727	1,653
Weighted average interest rate on short-term borrowings outstanding at end of year		1.40%	1.70%
Commercial paper program [Member]
Short-term Debt [Line Items]
Total short-term borrowings		245	292
Weighted average interest rate on short-term borrowings outstanding at end of year		0.90%
Revolving credit facility [Member]
Short-term Debt [Line Items]
Total short-term borrowings		0	772
364-day term loan facility [Member]
Short-term Debt [Line Items]
Total short-term borrowings		175	300
Weighted average interest rate on short-term borrowings outstanding at end of year		1.90%
Debt instrument, term	364 days	364 days
Other short-term bank loans [Member]
Short-term Debt [Line Items]
Total short-term borrowings		$ 257	$ 216