Stock-Based Compensation (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	May 20, 2010	May 17, 2007
Additional Stock Based Compensation (Textuals) [Abstract]
Unrecognized stock-based compensation expense	$ 40,000,000
Stock Based Compensation (Textuals) [Abstract]
Shares reserved for issuance	27,000,000			11,000,000	19,000,000
Shares available for future grants	16,000,000
Maximum number of shares of common stock available for sale under employee stock purchase plan	2,000,000
Maximum annual amount for purchase of common stock per participant under employee stock purchase plan	15,000
Number of shares eligible for employee to purchase per offering period	750
Percentage of purchase price is the lower of closing price of either the first or the last day of the offering period	85.00%
No. of shares purchases by employees	194,000
Average price of shares purchased	$ 23.75
Shares available for purchase under Employee stock purchase plan	616,000
Amortization of stock-based awards	36,000,000	52,000,000	48,000,000
Estimated forfeitures under employee stock-based awards	1,000,000
Unrecognized stock-based compensation expense, Weighted-average period of recognition in years	1 year 10 months
Total intrinsic value of options exercised	69,000,000	55,000,000	20,000,000
Cash received from stock option exercises	50,000,000	45,000,000	7,000,000
Tax benefit realized from stock options exercise	25,000,000	21,000,000	7,000,000
Stock Options Outstanding, Weighted Average Remaining Contractual Life	5 years 2 months
Stock Options Exercisable, Weighted Average Remaining Contractual Life	4 years
Performance based nonvested restricted stock units as a percent of total nonvested restricted stock units outstanding	30.00%
Range of vested shares based on the extent to which certain financial targets are achieved	zero percent to 200 percent of the original grant amount
Discontinued operations [Member]
Stock Based Compensation (Textuals) [Abstract]
Amortization of stock-based awards		18,000,000	14,000,000
Nonvested Restricted Stock Units [Member]
Additional Stock Based Compensation (Textuals) [Abstract]
Unrecognized stock-based compensation expense	37,000,000
Stock options [Member]
Additional Stock Based Compensation (Textuals) [Abstract]
Unrecognized stock-based compensation expense	$ 3,000,000