Share-Based Compensation - Summary of Stock Options Activity (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Number of Shares
Beginning of period (in shares) | shares	2,374
Granted (in shares) | shares	169
Exercised (in shares) | shares	(351)
Forfeited (in shares) | shares	(65)
Expired (in shares) | shares	(6)
End of period (in shares) | shares	2,121
Weighted Average Exercise Price
Beginning of period (in dollars per share) | $ / shares	$ 29.22
Granted (in dollars per share) | $ / shares	52.06
Exercised (in dollars per share) | $ / shares	25.12
Forfeited (in dollars per share) | $ / shares	35.50
Expired (in dollars per share) | $ / shares	27.10
End of period (in dollars per share) | $ / shares	$ 31.53