Stock Plans - Summary of Stock Option Activity (Details)	3 Months Ended
	Mar. 31, 2016 $ / shares shares
Shares
Outstanding, beginning balance (in shares) | shares	1,694,675
Granted (in shares) | shares	235,233
Exercised (in shares) | shares	(72,196)
Outstanding, ending balance (in shares) | shares	1,857,712
Exercisable (in shares) | shares	1,340,863
Weighted Average Exercise Price (dollars per share)
Outstanding, beginning balance (dollars per share) | $ / shares	$ 36.69
Granted (dollars per share) | $ / shares	44.50
Exercised (dollars per share) | $ / shares	40.07
Outstanding, ending balance (dollars per share) | $ / shares	37.54
Exercisable (dollars per share) | $ / shares	$ 33.71