Share-Based Compensation - Summary of Stock Award Activity (Details) shares in Thousands	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Number of Shares
December 31, 2015 (in shares) | shares	2,461
Granted (in shares) | shares	569
Cancelled (in shares) | shares	(66)
Exercised (in shares) | shares	(238)
June 30, 2016 (in shares) | shares	2,726
Weighted Average Exercise Price
December 31, 2015 (in dollars per share) | $ / shares	$ 22.16
Granted (in dollars per share) | $ / shares	34.14
Cancelled (in dollars per share) | $ / shares	29.31
Exercised (in dollars per share) | $ / shares	20.25
June 30, 2016 (in dollars per share) | $ / shares	$ 24.65