Stock-Based Compensation - Summary of Stock Options Outstanding (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2019 $ / shares shares
Number of Shares
Beginning of period (in shares) | shares	2,121
Granted (in shares) | shares	188
Exercised (in shares) | shares	(127)
Forfeited (in shares) | shares	(20)
Expired (in shares) | shares	(13)
End of period (in shares) | shares	2,149
Weighted Average Exercise Price
Beginning of period (in dollars per share) | $ / shares	$ 31.53
Granted (in dollars per share) | $ / shares	40.49
Exercised (in dollars per share) | $ / shares	24.44
Forfeited (in dollars per share) | $ / shares	36.50
Expired (in dollars per share) | $ / shares	31.00
End of period (in dollars per share) | $ / shares	$ 32.69