Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2011

Stock-Based Compensation [Abstract]

Schedule of stock-based compensation, allocation of recognized period costs

The following table reflects activity related to our stock-based compensation arrangements (in millions):

	Year Ended December 31,
	2011		2010		2009
Stock-based compensation expense	$	58	$	54	$	68
Tax benefit recognized on stock-based compensation expense	20		19		24
Tax benefit realized for tax deductions resulting from exercises and vestings	35		23		9
Effect of tax deductions in excess of recognized stock-based compensation expense reported as a financing cash flow	23		11		5

Summary of weighted-average assumptions used in fair value measurements

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A summary of the weighted-average assumptions used in our fair value measurements is presented in the table below.

	Year Ended December 31,
	2011		2010		2009
Expected life in years	6.0		6.0		6.0
Expected volatility	49.30	%	48.21	%	47.8	%
Expected dividend yield	2.28	%	1.05	%	3.1	%
Risk-free interest rate	1.44	%	1.83	%	2.8	%

Summary of stock option awards

A summary of the status of our stock option awards is presented in the table below.

	Number of Stock Options		Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term	Aggregate Intrinsic Value
					(in years)	(in millions)
Outstanding as of January 1, 2011	24,379,558		$	24.83
Granted	370,025		26.30
Exercised	(4,345,678	)	11.56
Forfeited	(497,319	)	50.29
Outstanding as of December 31, 2011	19,906,586		27.11		3.5	$	67
Exercisable as of December 31, 2011	17,864,926		27.05		3.0	64

Summary of restricted stock awards

A summary of the status of our restricted stock awards is presented in the table below.

	Number of Shares		Weighted- Average Grant-Date Fair Value Per Share
Nonvested shares as of January 1, 2011	3,360,213		$	21.05
Granted	1,297,464		26.32
Vested	(1,350,658	)	23.17
Forfeited	(57,929	)	20.66
Nonvested shares as of December 31, 2011	3,249,090		22.28

Summary of performance awards

There were two grants of performance awards during the year ended December 31, 2011 as follows (dollars in millions). The first grant shown below represents the second tranche of vesting awards from the performance awards authorized by our compensation committee in 2010. The second grant shown represents the first tranche of vesting awards from the performance awards authorized by our compensation committee in 2011.

	Awards Granted	Expected Conversion Rate	Fair Value Per Share
First grant	222,250	50%	$	25.70
Second grant	246,691	—%	25.70
Total	468,941

A summary of the status of our performance awards considered granted is presented below.

	Nonvested Awards		Vested Awards
Awards outstanding as of January 1, 2011	253,611		24,219
Granted	468,941		—
Vested	(31,361	)	31,361
Converted	—		—
Forfeited	—		(30,945	)
Awards outstanding as of December 31, 2011	691,191		24,635