Stock-Based Compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010 Y	Dec. 31, 2009 Y	Dec. 31, 2008
Stock-based Compensation Arrangements Activity
Stock-based compensation expense	$ 58,000,000	$ 54,000,000	$ 68,000,000
Tax benefit recognized on stock-based compensation expense	20,000,000	19,000,000	24,000,000
Tax benefit realized for tax deductions resulting from exercises and vestings	35,000,000	23,000,000	9,000,000
Effect of tax deductions in excess of recognized stock-based compensation expense reported as a financing cash flow	23,000,000	11,000,000	5,000,000
Stock Based Compensation (Textual)
Number of vesting tranches remaining to be granted under performance awards issued	2
Omnibus Stock Incentive Plan [Member]
Stock Based Compensation (Textual)
Number of shares of common stock available to be awarded under stock-based compensation plans	18,498,630
Recently Terminated Plans [Member]
Stock Based Compensation (Textual)
Number of shares of common stock available to be awarded under stock-based compensation plans	0
Restricted Stock Plan for NonEmployee Directors [Member]
Stock Based Compensation (Textual)
Number of shares of common stock available to be awarded under stock-based compensation plans	8,289
Annual grant of common stock receivable to non-employee director	160,000
Granting of stock on first anniversary of grant date	0.3333
Granting of stock on second anniversary of grant date	0.6666
Grants vest on common stock grants after second grant on the first anniversary of the grant date	1
Employee Stock Incentive Plan [Member]
Stock Based Compensation (Textual)
Number of shares of common stock available to be awarded under stock-based compensation plans	536,141
Formerly Maintained Plans [Member]
Stock Based Compensation (Textual)
Number of shares of common stock available to be awarded under stock-based compensation plans	0
Stock Options [Member]
Summary of Weighted-Average Assumptions Used in Fair Value Measurements
Expected life in years	6	6	6
Expected volatility	49.30%	48.21%	47.80%
Expected dividend yield	2.28%	1.05%	3.10%
Risk-free interest rate	1.44%	1.83%	2.80%
Summary of stock option awards
Stock options outstanding as of beginning of year	24,379,558
Number of Stock Options, Granted	370,025
Number of Stock Options, Exercised	(4,345,678)
Number of Stock Options, Forfeited	(497,319)
Stock options outstanding as of end of year	19,906,586	24,379,558
Number of Stock Options, Exercisable as of December 31, 2010	17,864,926
Weighted-Average Exercise Price Per Share Outstanding, Beginning Balance	$ 24.83
Weighted-Average Exercise Price Per Share, granted	$ 26.30
Weighted-Average Exercise Price Per Share, Exercised	$ 11.56
Weighted-Average Exercise Price Per Share, Forfeited	$ 50.29
Weighted-Average Exercise Price Per Share Outstanding, Ending Balance	$ 27.11	$ 24.83
Weighted-Average Remaining Contractual Term, Outstanding at December 31, 2010	3.5
Weighted-Average Exercise Price Per Share, Exercisable at December 31, 2010	$ 27.05
Weighted-Average Remaining Contractual Term, Exercisable at December 31, 2010	3
Aggregate Intrinsic Value, Outstanding at December 31, 2010	67,000,000
Aggregate Intrinsic Value, Exercisable at December 31, 2011	64,000,000
Stock Based Compensation (Textual)
Vesting period of stock-based payment awards granted	3 years			5 years
Weighted average grant date fair value of stock option	$ 10.10	$ 8.17	$ 6.91
Intrinsic value of stock options exercised	63,000,000	25,000,000	12,000,000
Cash received from exercise of stock options	49,000,000	20,000,000	11,000,000
Unrecognized share-based compensation cost related to outstanding unvested awards	9,000,000
Weighted-average period of recognition for unrecognized compensation costs on nonvested awards	1
Restricted Stock Award [Member]
Summary of Awards Other Than Options
Nonvested awards, Beginning Balance	3,360,213
Shares, Granted	1,297,464
Shares, Vested	(1,350,658)
Shares, Forfeited	(57,929)
Nonvested awards, Ending Balance	3,249,090	3,360,213
Weighted average grant date fair value, Beginning Balance	$ 21.05
Weighted average grant date fair value, Granted	$ 26.32
Weighted average grant date fair value, Vested	$ 23.17
Weighted average grant date fair value, Forfeited	$ 20.66
Weighted average grant date fair value, Ending Balance	$ 22.28	$ 21.05
Stock Based Compensation (Textual)
Vesting period of stock-based payment awards granted	three to five years
Unrecognized share-based compensation cost related to outstanding unvested awards	44,000,000
Weighted-average period of recognition for unrecognized compensation costs on nonvested awards	2
Total fair value of restricted stock vested	$ 32,000,000	$ 25,000,000	$ 12,000,000
Restricted Stock Awards - Nonemployee [Member]
Stock Based Compensation (Textual)
Number of installments in initial grant of common stock	3
Vesting period of stock-based payment awards granted	one to three years
Performance Awards [Member]
Summary of Awards Other Than Options
Nonvested awards, Beginning Balance	253,611
Shares, Granted	468,941
Shares, Vested	(31,361)
Shares, Converted	0
Shares, Forfeited	0
Nonvested awards, Ending Balance	691,191
Stock Based Compensation (Textual)
Vesting period of stock-based payment awards granted	1 year
Performance award vesting rights	0.3333
Performance Awards - Vested [Member]
Summary of Awards Other Than Options
Vested awards, Beginning Balance	24,219
Shares, Granted	0
Shares, Vested	31,361
Shares, Converted	0
Shares, Forfeited	(30,945)
Vested awards, Ending Balance	24,635
Vesting Tranche - One [Member] | Performance Awards [Member]
Summary of Awards Other Than Options
Shares, Granted	246,691
Weighted average grant date fair value, Granted	$ 25.70
Conversion rate to common stock shares	0.00
Vesting Tranche - Two [Member] | Performance Awards [Member]
Summary of Awards Other Than Options
Shares, Granted	222,250
Weighted average grant date fair value, Granted	$ 25.70
Conversion rate to common stock shares	0.5
Minimum [Member] | Stock Options [Member]
Stock Based Compensation (Textual)
Number of installments of stock option exercises	3
Stock option award expiration period	7 years
Minimum [Member] | Performance Awards [Member]
Stock Based Compensation (Textual)
Performance awards range of conversion rates	0.00%
Maximum [Member] | Stock Options [Member]
Stock Based Compensation (Textual)
Number of installments of stock option exercises	5
Stock option award expiration period	10 years
Maximum [Member] | Performance Awards [Member]
Stock Based Compensation (Textual)
Performance awards range of conversion rates	200.00%