SCHEDULE II. VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Movement in valuation and qualifying accounts
Valuation allowance on deferred tax assets	$ 66	$ 662
Allowances for doubtful accounts, deducted from accounts receivable
Movement in valuation and qualifying accounts
Balance at Beginning of Period	27	31	29
Additions, Charged to Costs and Expenses	6	8	13
Deductions	(15)	(12)	(11)
Balance at End of Period	18	27	31
Valuation Allowance on deferred tax assets
Movement in valuation and qualifying accounts
Balance at Beginning of Period	662	785	686
Additions, Charged to Costs and Expenses	(539)	(36)	113
Additions, Charged to Other Accounts	(57)	(87)	(14)
Balance at End of Period	66	662	785
Certain net operating loss carryforward
Movement in valuation and qualifying accounts
Deferred tax asset written off	55
Primarily in other comprehensive income
Movement in valuation and qualifying accounts
Valuation allowance on deferred tax assets	$ 2