v3.19.1

Stock-Based Compensation - Stock Option Summary (Details) - USD ($) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Weighted Average Exercise Price (in dollars per share) | $ 9.38 | $ 8.01 | $ 6.36
Average Remaining Life (years) | 3 years 1 month 6 days |  |
Outstanding Shares (in shares) | 1,431,860 | 1,363,444 | 1,599,976
Exercisable Shares (in shares) | 643,610 | 644,472 |
Outstanding Shares, intrinsic value | $ 3,178,491 | $ 5,951,363 |
Exercisable Shares, intrinsic value | $ 2,399,743 | $ 4,271,277 |
Exercise Price Range 1 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Weighted Average Exercise Price (in dollars per share) | $ 6.63 | $ 5.00 |
Average Remaining Life (years) | 1 year | 1 year |
Outstanding Shares (in shares) | 283,886 | 211,952 |
Exercisable Shares (in shares) | 268,886 | 211,952 |
Exercise Price Range 2 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Weighted Average Exercise Price (in dollars per share) | $ 7.50 | $ 6.63 |
Average Remaining Life (years) | 2 years | 2 years |
Outstanding Shares (in shares) | 297,348 | 323,792 |
Exercisable Shares (in shares) | 207,898 | 218,868 |
Exercise Price Range 3 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Weighted Average Exercise Price (in dollars per share) | $ 8.50 | $ 7.50 |
Average Remaining Life (years) | 3 years | 3 years |
Outstanding Shares (in shares) | 222,276 | 328,900 |
Exercisable Shares (in shares) | 103,176 | 154,100 |
Exercise Price Range 4 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Weighted Average Exercise Price (in dollars per share) | $ 11.38 | $ 8.50 |
Average Remaining Life (years) | 5 years | 4 years |
Outstanding Shares (in shares) | 354,750 | 238,200 |
Exercisable Shares (in shares) | 0 | 59,552 |
Exercise Price Range 5 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Weighted Average Exercise Price (in dollars per share) | $ 12.38 | $ 12.38 |
Average Remaining Life (years) | 4 years | 5 years |
Outstanding Shares (in shares) | 266,600 | 260,600 |
Exercisable Shares (in shares) | 63,650 | 0 |
Exercise Price Range 6 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Weighted Average Exercise Price (in dollars per share) | $ 12.80 | $ 8.01 |
Average Remaining Life (years) | 4 years 9 months 18 days | 2 years 7 months 6 days |
Outstanding Shares (in shares) | 7,000 | 1,363,444 |
Exercisable Shares (in shares) | 0 | 644,472 |

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