Stock-Based Compensation - Summary of Stock Options Outstanding (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Number of Shares
December 31, 2016 (in shares) | shares	2,615
Granted (in shares) | shares	544
Canceled (in shares) | shares	(93)
Exercised (in shares) | shares	(513)
September 30, 2017 (in shares) | shares	2,553
Weighted Average Exercise Price
December 31, 2016 (in dollars per share) | $ / shares	$ 24.61
Granted (in dollars per share) | $ / shares	39.38
Canceled (in dollars per share) | $ / shares	33.66
Exercised (in dollars per share) | $ / shares	20.39
September 30, 2017 (in dollars per share) | $ / shares	$ 28.27