Stock-Based Compensation (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012 Year
Range 9.56 to 14.77
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares	558,182
Options Outstanding, Average Remaining Life (Years)	5.06
Options Outstanding, Average Exercise Price	$ 11.78
Options Exercisable, Number of Shares	536,257
Options Exercisable, Average Exercise Price	$ 11.79
Range of Exercise Prices, Lower Range Limit	$ 9.56
Range of Exercise Prices, Upper Range Limit	$ 14.77
Range 15.02 to 20.21
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares	749,810
Options Outstanding, Average Remaining Life (Years)	5.41
Options Outstanding, Average Exercise Price	$ 17.35
Options Exercisable, Number of Shares	584,414
Options Exercisable, Average Exercise Price	$ 17.85
Range of Exercise Prices, Lower Range Limit	$ 15.02
Range of Exercise Prices, Upper Range Limit	$ 20.21
Range 20.69 to 22.34
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares	566,438
Options Outstanding, Average Remaining Life (Years)	6.15
Options Outstanding, Average Exercise Price	$ 21.45
Options Exercisable, Number of Shares	358,104
Options Exercisable, Average Exercise Price	$ 21.89
Range of Exercise Prices, Lower Range Limit	$ 20.69
Range of Exercise Prices, Upper Range Limit	$ 22.34
Range 23.18 to 33.45
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares	352,715
Options Outstanding, Average Remaining Life (Years)	6.14
Options Outstanding, Average Exercise Price	$ 26.22
Options Exercisable, Number of Shares	238,515
Options Exercisable, Average Exercise Price	$ 26.19
Range of Exercise Prices, Lower Range Limit	$ 23.18
Range of Exercise Prices, Upper Range Limit	$ 33.45