Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Changes in unrecognized tax benefits
Gross amounts of unrecognized tax benefits, beginning of period	$ 334,000,000
Increases related to prior period tax positions	0
Decreases related to prior period tax positions	0
Increases related to current period tax positions	4,000,000
Settlements	(3,000,000)
Gross amounts of unrecognized tax benefits, end of period	335,000,000
Accrued interest and penalties	80,000,000	77,000,000
Undistributed earnings of foreign subsidiaries	5,000,000,000	14,000,000,000
Foreign earnings expected to be repatriated	9,000,000,000
Deferred tax liability on undistributed foreign earnings	3,000,000,000
Income taxes provided estimated earnings of foreign subsidiaries expected to be repatriated	$ 53,000,000