Stock Option and Compensation Plans - Options Outstanding and Exercisable by Exercise Price and Options Exercised (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($) $ / shares shares
Options Outstanding
Total Options Outstanding (in shares) | shares	3,423
Weighted Average Remaining Life (Years)	7 years 9 months 21 days
Weighted Average Exercise Price (in dollars per share)	$ 39.26
Aggregate Intrinsic Value of Options Outstanding | $	$ 38,226
Options Exercisable
Number Exercisable (in shares) | shares	1,399
Weighted Average Exercise Price (in dollars per share)	$ 30.18
Aggregate Intrinsic Value of Options Exercisable | $	$ 23,077
$0.12-$10.03
Options Outstanding
Total Options Outstanding (in shares) | shares	257
Weighted Average Remaining Life (Years)	5 years 7 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 6.77
Options Exercisable
Number Exercisable (in shares) | shares	158
Weighted Average Exercise Price (in dollars per share)	$ 4.74
Exercise prices, low end of range (in dollars per share)	0.12
Exercise prices, high end of range (in dollars per share)	$ 10.03
$10.04-$20.00
Options Outstanding
Total Options Outstanding (in shares) | shares	274
Weighted Average Remaining Life (Years)	6 years 8 months 26 days
Weighted Average Exercise Price (in dollars per share)	$ 13.44
Options Exercisable
Number Exercisable (in shares) | shares	151
Weighted Average Exercise Price (in dollars per share)	$ 13.48
Exercise prices, low end of range (in dollars per share)	10.04
Exercise prices, high end of range (in dollars per share)	$ 20.00
$20.01-$30.00
Options Outstanding
Total Options Outstanding (in shares) | shares	154
Weighted Average Remaining Life (Years)	7 years 1 month 6 days
Weighted Average Exercise Price (in dollars per share)	$ 25.56
Options Exercisable
Number Exercisable (in shares) | shares	102
Weighted Average Exercise Price (in dollars per share)	$ 25.51
Exercise prices, low end of range (in dollars per share)	20.01
Exercise prices, high end of range (in dollars per share)	$ 30.00
$30.01-$40.00
Options Outstanding
Total Options Outstanding (in shares) | shares	1,093
Weighted Average Remaining Life (Years)	6 years 11 months 3 days
Weighted Average Exercise Price (in dollars per share)	$ 32.67
Options Exercisable
Number Exercisable (in shares) | shares	699
Weighted Average Exercise Price (in dollars per share)	$ 33.05
Exercise prices, low end of range (in dollars per share)	30.01
Exercise prices, high end of range (in dollars per share)	$ 40.00
$40.01-$55.00
Options Outstanding
Total Options Outstanding (in shares) | shares	1,115
Weighted Average Remaining Life (Years)	8 years 10 months 1 day
Weighted Average Exercise Price (in dollars per share)	$ 46.24
Options Exercisable
Number Exercisable (in shares) | shares	267
Weighted Average Exercise Price (in dollars per share)	$ 45.65
Exercise prices, low end of range (in dollars per share)	40.01
Exercise prices, high end of range (in dollars per share)	$ 55.00
$55.01-$73.22
Options Outstanding
Total Options Outstanding (in shares) | shares	530
Weighted Average Remaining Life (Years)	9 years 3 months 16 days
Weighted Average Exercise Price (in dollars per share)	$ 71.26
Options Exercisable
Number Exercisable (in shares) | shares	22
Weighted Average Exercise Price (in dollars per share)	$ 70.28
Exercise prices, low end of range (in dollars per share)	55.01
Exercise prices, high end of range (in dollars per share)	$ 73.22