Stock-Based Compensation - Range of Exercise Prices (Details) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended |
Mar. 31, 2017 | Mar. 31, 2016 |
Stock options to purchase common stock | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Total intrinsic value of stock options exercised during the period | $ 0.5 | $ 0.1 |
Unrecognized compensation expense related to unvested stock options | $ 28.4 | |
Expected weighted average period for recognizing unrecognized compensation expense | 2 years 8 months 12 days | |
Performance-based options | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Unrecognized compensation expense related to unvested stock options | $ 1.1 | |
$3.03 to $3.40 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | $ 3.03 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 3.40 | |
Number of Options outstanding (in shares) | 841,850 | |
Weighted Average Remaining Contractual Term | 5 years 4 months 2 days | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 3.34 | |
Number of Options exercisable (in shares) | 841,850 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 3.34 | |
$3.60 to $6.90 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 3.60 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 6.90 | |
Number of Options outstanding (in shares) | 452,003 | |
Weighted Average Remaining Contractual Term | 4 years 3 months | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 5.82 | |
Number of Options exercisable (in shares) | 414,503 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 5.72 | |
$6.96 to $10.85 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 6.96 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 10.85 | |
Number of Options outstanding (in shares) | 1,096,296 | |
Weighted Average Remaining Contractual Term | 9 years 18 days | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 10.76 | |
Number of Options exercisable (in shares) | 23,751 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 6.96 | |
$11.14 to $12.58 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 11.14 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 12.58 | |
Number of Options outstanding (in shares) | 1,121,225 | |
Weighted Average Remaining Contractual Term | 6 years 9 months 15 days | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 12.18 | |
Number of Options exercisable (in shares) | 664,466 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 12.21 | |
$12.66 to $13.58 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 12.66 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 13.58 | |
Number of Options outstanding (in shares) | 187,880 | |
Weighted Average Remaining Contractual Term | 8 years 2 months 1 day | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 13.24 | |
Number of Options exercisable (in shares) | 68,887 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 13.30 | |
$13.67 to $13.67 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 13.67 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 13.67 | |
Number of Options outstanding (in shares) | 880,750 | |
Weighted Average Remaining Contractual Term | 9 years 9 months 7 days | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 13.67 | |
$13.94 to $16.07 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 13.94 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 16.07 | |
Number of Options outstanding (in shares) | 867,990 | |
Weighted Average Remaining Contractual Term | 7 years 5 months 19 days | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 15.18 | |
Number of Options exercisable (in shares) | 467,219 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 15.13 | |
$16.09 to $16.54 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 16.09 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 16.54 | |
Number of Options outstanding (in shares) | 775,528 | |
Weighted Average Remaining Contractual Term | 8 years 6 months 18 days | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 16.18 | |
Number of Options exercisable (in shares) | 215,355 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 16.17 | |
$17.14 to $22.76 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 17.14 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 22.76 | |
Number of Options outstanding (in shares) | 1,427,631 | |
Weighted Average Remaining Contractual Term | 7 years 6 months 15 days | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 21.27 | |
Number of Options exercisable (in shares) | 714,903 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 21 | |
$22.84 to $27.38 | | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range | | |
Range of Exercise Prices lower range limit (in dollars per share) | 22.84 | |
Range of Exercise Prices upper range limit (in dollars per share) | $ 27.38 | |
Number of Options outstanding (in shares) | 67,837 | |
Weighted Average Remaining Contractual Term | 8 years 1 month 17 days | |
Outstanding Options, Weighted Average Exercise Price (in dollars per share) | $ 23.78 | |
Number of Options exercisable (in shares) | 26,023 | |
Exercisable Options, Weighted Average Exercise Price (in dollars per share) | $ 23.79 | |