Stock-Based Compensation (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012
Information about stock options outstanding
Low end of exercise price range (in dollars per share)	$ 11.88
High end of exercise price range (in dollars per share)	$ 61.82
Outstanding options
Number outstanding (in shares)	11,805,688
Weighted-average remaining contractual life (years)	3 years 11 months 19 days
Weighted-average exercise price (in dollars per share)	$ 31.44
Exercisable options
Number outstanding (in shares)	7,892,688
Weighted-average exercise price (in dollars per share)	$ 30.55
Exercise Price Range $11.88 to $29.22
Information about stock options outstanding
Low end of exercise price range (in dollars per share)	$ 11.88
High end of exercise price range (in dollars per share)	$ 29.22
Outstanding options
Number outstanding (in shares)	4,779,919
Weighted-average remaining contractual life (years)	2 years 10 months 24 days
Weighted-average exercise price (in dollars per share)	$ 25.29
Exercisable options
Number outstanding (in shares)	3,535,544
Weighted-average exercise price (in dollars per share)	$ 25.27
Exercise Price Range $29.34 to $35.15
Information about stock options outstanding
Low end of exercise price range (in dollars per share)	$ 29.34
High end of exercise price range (in dollars per share)	$ 35.15
Outstanding options
Number outstanding (in shares)	4,116,268
Weighted-average remaining contractual life (years)	4 years 5 months 5 days
Weighted-average exercise price (in dollars per share)	$ 32.68
Exercisable options
Number outstanding (in shares)	3,033,643
Weighted-average exercise price (in dollars per share)	$ 31.81
Exercise Price Range $35.75 to $61.82
Information about stock options outstanding
Low end of exercise price range (in dollars per share)	$ 35.75
High end of exercise price range (in dollars per share)	$ 61.82
Outstanding options
Number outstanding (in shares)	2,909,501
Weighted-average remaining contractual life (years)	5 years 29 days
Weighted-average exercise price (in dollars per share)	$ 39.78
Exercisable options
Number outstanding (in shares)	1,323,501
Weighted-average exercise price (in dollars per share)	$ 41.75