Stock-Based Compensation (Details 2) (Stock Options, USD $)	12 Months Ended
	Dec. 31, 2013
Information of stock options by exercise price range.
Number Outstanding (in shares)	4,245,712
Outstanding Weighted-Average Exercise Price (in dollars per share)	$ 13.65
Outstanding Weighted-Average Remaining Life	5 years 9 months 7 days
Number Exercisable (in shares)	2,299,362
Exercisable Weighted-Average Exercise Price (in dollars per share)	$ 17.44
$ 0.00 - 6.99
Information of stock options by exercise price range.
Range of Exercise Prices, minimum (in dollars per share)	$ 0.00
Range of Exercise Prices, maximum (in dollars per share)	$ 6.99
Number Outstanding (in shares)	352,000
Outstanding Weighted-Average Exercise Price (in dollars per share)	$ 6.04
Outstanding Weighted-Average Remaining Life	5 years 1 month 6 days
Number Exercisable (in shares)	249,875
Exercisable Weighted-Average Exercise Price (in dollars per share)	$ 6.04
$ 7.00 - 10.99
Information of stock options by exercise price range.
Range of Exercise Prices, minimum (in dollars per share)	$ 7.00
Range of Exercise Prices, maximum (in dollars per share)	$ 10.99
Number Outstanding (in shares)	1,657,100
Outstanding Weighted-Average Exercise Price (in dollars per share)	$ 8.61
Outstanding Weighted-Average Remaining Life	8 years 10 months 10 days
Number Exercisable (in shares)	209,125
Exercisable Weighted-Average Exercise Price (in dollars per share)	$ 8.70
$ 11.00 - 11.99
Information of stock options by exercise price range.
Range of Exercise Prices, minimum (in dollars per share)	$ 11.00
Range of Exercise Prices, maximum (in dollars per share)	$ 11.99
Number Outstanding (in shares)	623,500
Outstanding Weighted-Average Exercise Price (in dollars per share)	$ 11.90
Outstanding Weighted-Average Remaining Life	6 years 1 month 6 days
Number Exercisable (in shares)	350,500
Exercisable Weighted-Average Exercise Price (in dollars per share)	$ 11.90
$ 12.00 - 15.99
Information of stock options by exercise price range.
Range of Exercise Prices, minimum (in dollars per share)	$ 12.00
Range of Exercise Prices, maximum (in dollars per share)	$ 15.99
Number Outstanding (in shares)	498,500
Outstanding Weighted-Average Exercise Price (in dollars per share)	$ 14.16
Outstanding Weighted-Average Remaining Life	5 years 6 months 7 days
Number Exercisable (in shares)	375,250
Exercisable Weighted-Average Exercise Price (in dollars per share)	$ 14.71
$ 16.00 - 24.49
Information of stock options by exercise price range.
Range of Exercise Prices, minimum (in dollars per share)	$ 16.00
Range of Exercise Prices, maximum (in dollars per share)	$ 24.49
Number Outstanding (in shares)	426,937
Outstanding Weighted-Average Exercise Price (in dollars per share)	$ 21.77
Outstanding Weighted-Average Remaining Life	7 months 13 days
Number Exercisable (in shares)	426,937
Exercisable Weighted-Average Exercise Price (in dollars per share)	$ 21.77
$ 24.50 - 28.85
Information of stock options by exercise price range.
Range of Exercise Prices, minimum (in dollars per share)	$ 24.50
Range of Exercise Prices, maximum (in dollars per share)	$ 28.85
Number Outstanding (in shares)	687,675
Outstanding Weighted-Average Exercise Price (in dollars per share)	$ 25.86
Outstanding Weighted-Average Remaining Life	1 year 8 months 23 days
Number Exercisable (in shares)	687,675
Exercisable Weighted-Average Exercise Price (in dollars per share)	$ 25.86