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
Mar. 31, 2014
item
Restricted Stock
 
Stock-Based compensation  
Award vesting rights proportion (as a percent) 33.00%
Number of vesting rights anniversaries 3
Number of Shares  
Balance at the beginning of the period (in shares) 901,551
Granted (in shares) 240,626
Vested (in shares) (116,706)
Forfeited (in shares) (10,324)
Balance at the end of the period (in shares) 1,015,147
Weighted-Average Grant Date Fair Value per Share  
Balance at the beginning of the period (in dollars per share) $ 16.50
Granted (in dollars per share) $ 41.83
Vested (in dollars per share) $ 14.22
Forfeited (in dollars per share) $ 26.94
Balance at the end of the period (in dollars per share) $ 22.69