Impairment of Long Lived Assets (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended					3 Months Ended			9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Mar. 31, 2011	Sep. 30, 2012	Sep. 30, 2011
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets (excluding goodwill)	$ 48	$ 6	$ 28	$ 9	$ 74
Impairment charge related to computer software and equipment		3
Impairments of long-lived assets						$ 48	$ 9	$ 9	$ 85	$ 92
Fair value measurments, valuation processes, description									multiple period excess earnings method
Tax rate									15.00%
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Fair value inputs, discount rate									15.00%
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Fair value inputs, discount rate									25.00%