Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Details 4)

v2.4.0.8
Stock-Based Compensation (Details 4) (Restricted Stock, USD $)
3 Months Ended 9 Months Ended
Sep. 30, 2013
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Jun. 30, 2013
Mar. 31, 2013
Sep. 30, 2013
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Restricted Stock
       
Stock-Based compensation        
Award vesting rights proportion (as a percent)       33.00%
Number of vesting rights anniversaries 3     3
Number of Shares        
Balance at the beginning of the period (in shares) 810,246 857,041 758,990 758,990
Granted (in shares) 101,908 105,858 172,212  
Vested (in shares)     (70,964)  
Forfeited (in shares) (12,981) (152,653) (3,197)  
Balance at the end of the period (in shares) 899,173 810,246 857,041 899,173
Weighted-Average Grant Date Fair Value per Share        
Balance at the beginning of the period (in dollars per share) $ 14.51 $ 13.07 $ 12.49 $ 12.49
Granted (in dollars per share) $ 26.74 $ 18.29 $ 15.34  
Forfeited (in dollars per share) $ 14.10 $ 12.54 $ 13.78  
Balance at the end of the period (in dollars per share) $ 18.93 $ 14.51 $ 13.07 $ 18.93