Equity - Stock Incentive Plans (Details) | 3 Months Ended |
Mar. 31, 2017USD ($)plan$ / sharesshares |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
Number of share-based compensation plans | plan | 4 |
Number of shares [Roll forward] | |
Outstanding, beginning of period (in shares) | shares | 12,552,608 |
Granted (in shares) | shares | 0 |
Exercised (in shares) | shares | (387,653) |
Unvested options forfeited (in shares) | shares | (22,971) |
Vested options expired (in shares) | shares | (56,329) |
Outstanding, end of period (in shares) | shares | 12,085,655 |
Vested at end of period (in shares) | shares | 11,824,156 |
Exercisable options, vested and expected to vest (in shares) | shares | 12,057,583 |
Weighted-Average Exercise Price [Roll forward] | |
Outstanding, weighted average exercise price, beginning of period (in dollars per share) | $ 3.61 |
Granted, weighted average exercise price (in dollars per share) | 0 |
Exercised, weighted average exercise price (in dollars per share) | 4.68 |
Unvested options forfeited, weighted-average exercise price (in dollars per share) | 6.46 |
Vested options expired, weighted-average exercise price (in dollars per share) | 5.80 |
Outstanding, weighted average exercise price, end of period (in dollars per share) | 3.55 |
Vested at end of period, weighted average exercise price (in dollars per share) | 3.48 |
Vested and expected to vest, weighted average exercise price (in dollars per share) | $ 3.55 |
Stock options, additional disclosures [Abstract] | |
Outstanding Options, weighted average remaining contractual term (in years) | 5 years 2 months 27 days |
Vested at end of period, weighted average remaining contractual term (in years) | 5 years 2 months 12 days |
Vested and expected to vest, weighted average remaining contractual term (in years) | 5 years 2 months 27 days |
Outstanding, aggregate intrinsic value | $ | $ 72,155,029 |
Vested at end of period, aggregate intrinsic value | $ | 71,633,353 |
Vested or expected to vest, aggregate intrinsic value | $ | 72,148,754 |
Exercised options, intrinsic value | $ | $ 1,665,512 |
Number of outstanding options (in shares) | shares | 12,085,655 |
Outstanding Options, weighted average remaining contractual term (in years) | 5 years 2 months 27 days |
Outstanding Options, weighted average exercise price (in dollars per share) | $ 3.55 |
Number of exercisable options (in shares) | shares | 11,824,156 |
Exercisable Options, weighted average exercise price (in dollars per share) | $ 3.48 |
Total unrecognized compensation expense | $ | $ 427,135 |
$0.50 - $0.76 | |
Stock options, additional disclosures [Abstract] | |
Outstanding Options, weighted average remaining contractual term (in years) | 2 years 1 month 6 days |
Exercise Price Range, lower range limit (in dollars per share) | $ 0.50 |
Exercise Price Range, upper range limit (in dollars per share) | $ 0.76 |
Number of outstanding options (in shares) | shares | 431,429 |
Outstanding Options, weighted average remaining contractual term (in years) | 2 years 1 month 6 days |
Outstanding Options, weighted average exercise price (in dollars per share) | $ 0.72 |
Number of exercisable options (in shares) | shares | 431,429 |
Exercisable Options, weighted average exercise price (in dollars per share) | $ 0.72 |
$0.87 - $1.35 | |
Stock options, additional disclosures [Abstract] | |
Outstanding Options, weighted average remaining contractual term (in years) | 4 years 4 months 24 days |
Exercise Price Range, lower range limit (in dollars per share) | $ 0.87 |
Exercise Price Range, upper range limit (in dollars per share) | $ 1.35 |
Number of outstanding options (in shares) | shares | 4,322,236 |
Outstanding Options, weighted average remaining contractual term (in years) | 4 years 4 months 24 days |
Outstanding Options, weighted average exercise price (in dollars per share) | $ 1.19 |
Number of exercisable options (in shares) | shares | 4,318,569 |
Exercisable Options, weighted average exercise price (in dollars per share) | $ 1.19 |
$1.40 - $2.45 | |
Stock options, additional disclosures [Abstract] | |
Outstanding Options, weighted average remaining contractual term (in years) | 3 years 9 months 18 days |
Exercise Price Range, lower range limit (in dollars per share) | $ 1.40 |
Exercise Price Range, upper range limit (in dollars per share) | $ 2.45 |
Number of outstanding options (in shares) | shares | 1,362,424 |
Outstanding Options, weighted average remaining contractual term (in years) | 3 years 9 months 18 days |
Outstanding Options, weighted average exercise price (in dollars per share) | $ 1.92 |
Number of exercisable options (in shares) | shares | 1,362,424 |
Exercisable Options, weighted average exercise price (in dollars per share) | $ 1.92 |
$2.66 - $3.99 | |
Stock options, additional disclosures [Abstract] | |
Outstanding Options, weighted average remaining contractual term (in years) | 5 years 7 months 6 days |
Exercise Price Range, lower range limit (in dollars per share) | $ 2.66 |
Exercise Price Range, upper range limit (in dollars per share) | $ 3.99 |
Number of outstanding options (in shares) | shares | 850,513 |
Outstanding Options, weighted average remaining contractual term (in years) | 5 years 7 months 6 days |
Outstanding Options, weighted average exercise price (in dollars per share) | $ 3.07 |
Number of exercisable options (in shares) | shares | 830,513 |
Exercisable Options, weighted average exercise price (in dollars per share) | $ 3.07 |
$4.19 - $6.38 | |
Stock options, additional disclosures [Abstract] | |
Outstanding Options, weighted average remaining contractual term (in years) | 6 years 2 months 12 days |
Exercise Price Range, lower range limit (in dollars per share) | $ 4.19 |
Exercise Price Range, upper range limit (in dollars per share) | $ 6.38 |
Number of outstanding options (in shares) | shares | 2,808,206 |
Outstanding Options, weighted average remaining contractual term (in years) | 6 years 2 months 12 days |
Outstanding Options, weighted average exercise price (in dollars per share) | $ 5.37 |
Number of exercisable options (in shares) | shares | 2,712,379 |
Exercisable Options, weighted average exercise price (in dollars per share) | $ 5.34 |
$6.45 - $9.78 | |
Stock options, additional disclosures [Abstract] | |
Outstanding Options, weighted average remaining contractual term (in years) | 6 years 10 months 24 days |
Exercise Price Range, lower range limit (in dollars per share) | $ 6.45 |
Exercise Price Range, upper range limit (in dollars per share) | $ 9.78 |
Number of outstanding options (in shares) | shares | 2,209,847 |
Outstanding Options, weighted average remaining contractual term (in years) | 6 years 10 months 24 days |
Outstanding Options, weighted average exercise price (in dollars per share) | $ 7.30 |
Number of exercisable options (in shares) | shares | 2,107,346 |
Exercisable Options, weighted average exercise price (in dollars per share) | $ 7.28 |
$9.90- $10.99 | |
Stock options, additional disclosures [Abstract] | |
Outstanding Options, weighted average remaining contractual term (in years) | 7 years 8 months 12 days |
Exercise Price Range, lower range limit (in dollars per share) | $ 9.90 |
Exercise Price Range, upper range limit (in dollars per share) | $ 10.99 |
Number of outstanding options (in shares) | shares | 101,000 |
Outstanding Options, weighted average remaining contractual term (in years) | 7 years 8 months 12 days |
Outstanding Options, weighted average exercise price (in dollars per share) | $ 10.40 |
Number of exercisable options (in shares) | shares | 61,496 |
Exercisable Options, weighted average exercise price (in dollars per share) | $ 10.43 |