v2.4.0.6

Stock Incentive Plans Restricted Stock Units (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended					12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012 Long-Term Incentive Plan [Member]	Mar. 31, 2011 Long-Term Incentive Plan [Member]	Mar. 31, 2012 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member]	Mar. 31, 2012 Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation awards reclassified from equity to liability during the period.	$ 97
RSUs Outstanding at Balance Sheet Date					22.5		27.5
Granted			6.0	5.0	6.7
Settled					(1.4)
Forfeited or expired					(0.3)
RSUs unvested and expected to vest					18.5
RSUs vested and payable					8.3
RSUs Outstanding, Weighted Average Grant Date Fair Value at Balance Sheet Date					$ 23.12	$ 23.01
Grants in Period, Weighted Average Grant Date Fair Value					$ 25.99
Settled, Weighted Average Grant Date Fair Value					$ 34.64
Forfeited or expired, Weighted Average Grant Date Fair Value					$ 23.16
RSUs Weighted Average unvested and expected to vest					$ 23.74
RSUs Weighted Average vested and payable					$ 21.53
Weighted Average Remaining Contractual Term					1.4	1.1
RSUs Weighted Average Remaining Contractual Terms unvested and expected to vest					1.7
RSUs Weighted Average Remaining Contractual Terms vested and payable					0.0
Allocated Share-based Compensation Expense	72	53
Total unrecognized compensation expense for nonvested equity awards	361
Weighted average in years for total unrecognized compensation expense	1.8
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value	$ 49	$ 24

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