Stock Plans - Summary of Stock Option Activity (Details)	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Shares
Outstanding, beginning balance (in shares) | shares	1,694,675
Granted (in shares) | shares	235,233
Exercised (in shares) | shares	(111,990)
Forfeited (in shares) | shares	(6,173)
Outstanding, ending balance (in shares) | shares	1,811,745
Exercisable (in shares) | shares	1,316,322
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	39.17
Forfeited (in dollars per share) | $ / shares	46.95
Outstanding, ending balance (dollars per share) | $ / shares	37.51
Exercisable (dollars per share) | $ / shares	$ 33.79