Accumulated Other Comprehensive Income (AOCI) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income at Beginning of Period	$ (450)
Other comprehensive income before reclassifications	(167)
Amounts reclassified from AOCI	18
Tax effect	8
Net current period other comprehensive income	(141)
Balance of Accumulated Other Comprehensive Income at End of period	(591)
Foreign Currency Translation Adjustment [Member]
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income at Beginning of Period	136
Other comprehensive income before reclassifications	(148)
Tax effect	3
Net current period other comprehensive income	(145)
Balance of Accumulated Other Comprehensive Income at End of period	(9)
Deferred Gain (Loss) On Hedging Activities [Member]
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income at Beginning of Period	4	30
Other comprehensive income before reclassifications	9
Amounts reclassified from AOCI	3
Tax effect	(5)	15
Net current period other comprehensive income	7
Balance of Accumulated Other Comprehensive Income at End of period	11	4
Pension Liability Adjustment [Member]
Accumulated other comprehensive income (loss)
Balance of Accumulated Other Comprehensive Income at Beginning of Period	(590)
Other comprehensive income before reclassifications	9
Amounts reclassified from AOCI	15
Tax effect	(1)
Net current period other comprehensive income	23
Balance of Accumulated Other Comprehensive Income at End of period	(567)
Unrealized Gain (Loss) On Investments [Member]
Accumulated other comprehensive income (loss)
Other comprehensive income before reclassifications	(37)
Tax effect	11
Net current period other comprehensive income	(26)
Balance of Accumulated Other Comprehensive Income at End of period	$ (26)