Share-Based Compensation (Summary of Stock Option Activity) (Details) - $ / shares	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Shares [Roll Forward]
Outstanding, beginning of period (in shares)	1,235,150
Granted (in shares)	62,605
Exercised (in shares)	(398,805)
Forfeited or Expired (in shares)	(17,260)
Outstanding, end of period (in shares)	881,690
Exercisable, end of period (in shares)	419,112	724,501
Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning of period (weighted average exercise price)	$ 8.16
Granted (weighted average exercise price)	22.93
Exercised (weighted average exercise price)	6.35
Forfeited or Expired (weighted average exercise price)	11.82
Outstanding, end of period (weighted average exercise price)	9.95
Exercisable, end of period (weighted average exercise price)	$ 7.20	$ 6.22