Supplementary Stockholders' Equity Information Accumulated Other Comprehensive Income (Loss) (USD $) In Millions, unless otherwise specified	Total	Net Foreign Currency Translation Adjustment	Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	Other
Beginning Balance, Accumulated Other Comprehensive Income (Loss) at Dec. 31, 2011	$ (80)	$ 39	$ (90)	$ (29)
Change In Accumulated Other Comprehensive Income [Roll Forward]
Change	42	34	7	1
Ending Balance, Accumulated Other Comprehensive Income (Loss) at Mar. 31, 2012	$ (38)	$ 73	$ (83)	$ (28)