Stock-based Compensation (Details 2) (USD $)	6 Months Ended
	Jun. 30, 2013
Options exercisable and vested
Number of shares	3,357,658
Weighted-average remaining life	7 years
$20.00
Stock options outstanding and exercisable and vested by exercise price range
Exercise price (in dollars per share)	$ 20.00
Options exercisable and vested
Number of shares	3,207,658
Weighted-average remaining life	7 years
$28.80
Stock options outstanding and exercisable and vested by exercise price range
Exercise price (in dollars per share)	$ 28.80
Options exercisable and vested
Number of shares	150,000
Weighted-average remaining life	7 years 9 months 18 days