SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts [Roll Forward]
Balance at beginning of period	$ 61	$ 54	$ 42
Additions charged to costs and expenses	5	7	17
Other additions	0	0	0
Deductions	7	0	5
Balance at end of period	$ 59	$ 61	$ 54