Share-Based Compensation - Summary of Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Shares
Outstanding, beginning of period (in shares) | shares	1,450,704
Granted (in shares) | shares	410,960
Exercised (in shares) | shares	(189,415)
Forfeited or Expired (in shares) | shares	(105,140)
Outstanding, end of period (in shares) | shares	1,567,109
Exercisable, end of period (in shares) | shares	557,311
Weighted Average Exercise Price
Outstanding, beginning of period (weighted average exercise price) | $ / shares	$ 21.33
Granted (weighted average exercise price) | $ / shares	34.46
Exercised (weighted average exercise price) | $ / shares	11.93
Forfeited or Expired (weighted average exercise price) | $ / shares	29.93
Outstanding, end of period (weighted average exercise price) | $ / shares	25.27
Exercisable, end of period (weighted average exercise price) | $ / shares	$ 16.82