Stock Option and Compensation Plans - Options Outstanding and Exercisable by Exercise Price and Options Exercised (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Options Outstanding
Total Options Outstanding (in shares) | shares	3,359
Weighted Average Remaining Life (Years)	7 years 7 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 39.92
Aggregate Intrinsic Value of Options Outstanding | $	$ 254
Options Exercisable
Number Exercisable (in shares) | shares	1,531
Weighted Average Exercise Price (in dollars per share)	$ 31.19
Aggregate Intrinsic Value of Options Exercisable | $	$ 254
$0.12-$10.03
Options Outstanding
Total Options Outstanding (in shares) | shares	193
Weighted Average Remaining Life (Years)	5 years 3 months 18 days
Weighted Average Exercise Price (in dollars per share)	$ 6.84
Options Exercisable
Number Exercisable (in shares) | shares	137
Weighted Average Exercise Price (in dollars per share)	$ 5.52
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	273
Weighted Average Remaining Life (Years)	6 years 6 months
Weighted Average Exercise Price (in dollars per share)	$ 13.44
Options Exercisable
Number Exercisable (in shares) | shares	170
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)	6 years 9 months 18 days
Weighted Average Exercise Price (in dollars per share)	$ 25.56
Options Exercisable
Number Exercisable (in shares) | shares	114
Weighted Average Exercise Price (in dollars per share)	$ 25.53
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	1,087
Weighted Average Remaining Life (Years)	6 years 8 months 12 days
Weighted Average Exercise Price (in dollars per share)	$ 32.70
Options Exercisable
Number Exercisable (in shares) | shares	758
Weighted Average Exercise Price (in dollars per share)	$ 32.97
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	1,125
Weighted Average Remaining Life (Years)	8 years 7 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 46.22
Options Exercisable
Number Exercisable (in shares) | shares	319
Weighted Average Exercise Price (in dollars per share)	$ 45.49
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	527
Weighted Average Remaining Life (Years)	9 years
Weighted Average Exercise Price (in dollars per share)	$ 71.33
Options Exercisable
Number Exercisable (in shares) | shares	33
Weighted Average Exercise Price (in dollars per share)	$ 69.08
Exercise prices, low end of range (in dollars per share)	55.01
Exercise prices, high end of range (in dollars per share)	$ 73.22