Stock-Based Incentive Plan (Stock Option Activity) (Details) (USD $)	6 Months Ended
	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of shares under option, outstanding at beginning of period	16,616,617
Weighted average exercise price per share, outstanding at beginning of period	$ 19.54
Number of shares under option, options granted	1,527,535
Weighted average exercise price per share, options granted	$ 30.58
Number of shares under option, options exercised	(2,233,680)
Weighted average exercise price per share, options exercised	$ 17.79
Number of shares under option, options forfeited	(533,097)
Weighted average exercise price per share, options forfeited	$ 22.34
Number of shares under option, outstanding at end of period	15,377,375
Weighted average exercise price per share, outstanding at end of period	$ 20.81
Number of shares under option, vested and expected to vest at end of period	14,507,129
Weighted average exercise price per share, vested and expected to vest at end of period	$ 20.66
Number of shares under option, options exercisable at end of period	9,430,523
Weighted average exercise price per share - options exercisable at end of period	$ 18.67