Share-based Compensation (Details 5) (Stock awards, USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Stock awards
Share-Based Compensation
Exercise Price Range, Lower Range Limit (in dollars per share)	$ 1.84
Exercise Price Range, Upper Range Limit (in dollars per share)	$ 40.45
Option grants outstanding, weighted average remaining contractual life	6 years 9 months 7 days
Number of options, outstanding (in shares)	10,105,417	8,814,831
Number of options, exercisable (in shares)	5,455,070
Weighted average exercise price, Outstanding (in dollars per share)	$ 17.62	$ 15.26
Weighted average exercise price, Exercisable (in dollars per share)	$ 13.31
Weighted average remaining contractual term, Outstanding	6 years 9 months 7 days
Weighted average remaining contractual term, Exercisable	5 years 2 months 12 days
Aggregate intrinsic value, Outstanding	$ 218,737
Aggregate intrinsic value, Exercisable	$ 141,562