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Equity-Based Compensation (Tables) | 12 Months Ended
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Dec. 31, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract] |
Summary of Compensation Expense Connection with Awards | The Company recognized the following compensation expense in connection with awards that vested under the 2018 Plan, the 2015 Plan, the Prior Plan, and the Non-Employee Directors Plan along with the related tax benefits recognized during the years ended December 31 (in thousands):
| 2019 |  | 2018 |  | 2017
Expense recognized under the Prior Plan | $ | 192 |  |  | $ | 569 |  |  | $ | 1,059 |
Expense recognized under the 2015 Plan | 5,077 |  |  | 7,988 |  |  | 5,643 |
Expense recognized under the 2018 Plan | 6,731 |  |  | 188 |  |  | — |
Expense recognized under the Non-Employee Directors Plan | 570 |  |  | 444 |  |  | 420 |
Total stock compensation expense | $ | 12,570 |  |  | $ | 9,189 |  |  | $ | 7,122 |
Tax benefits recognized related to stock compensation expense | $ | 3,136 |  |  | $ | 2,509 |  |  | $ | 2,133 |
Schedule of Number of Awards and Weighted Average Grant Date Fair Value | The following table provides the number of stock options, stock units, and common stock granted during the years ended December 31, along with the weighted-average grant-date fair value of each award:
| 2019 |  | 2018 |  | 2017
Awards | Number of Awards |  | Weighted Average Grant Date Fair Value |  | Number of Awards |  | Weighted Average Grant Date Fair Value |  | Number of Awards |  | Weighted Average Grant Date Fair Value
Options | — |  |  | $ | — |  |  | — |  |  | $ | — |  |  | 25,000 |  |  | $ | 12.85 |
Deferred stock units | 7,509 |  |  | $ | 37.95 |  |  | 10,255 |  |  | $ | 35.96 |  |  | 10,170 |  |  | $ | 34.42 |
Common stock | 7,509 |  |  | $ | 37.95 |  |  | 2,113 |  |  | $ | 35.50 |  |  | 2,034 |  |  | $ | 34.42 |
Restricted stock units | 152,472 |  |  | $ | 39.73 |  |  | 116,174 |  |  | $ | 36.61 |  |  | 133,548 |  |  | $ | 36.56 |
Performance stock units | 183,908 |  |  | $ | 40.49 |  |  | 135,929 |  |  | $ | 33.63 |  |  | 108,748 |  |  | $ | 42.72 |
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions | The following table provides the weighted average assumptions used to value stock options issued during the year ended December 31:
Year of Grant |  | Fair Value |  | Expected Life (in years) |  | Expected Stock Volatility |  | Risk-free Interest Rate |  | Expected Dividend Yield
2017 |  | $ | 12.85 |  |  | 4.00 |  | 35.7 | % |  | 1.7 | % |  | — | %
Summary of Ranges of Outstanding and Exercisable Options | The following table summarizes the ranges of outstanding and exercisable options at December 31, 2019:
Range of Exercise Prices |  | Options Outstanding |  | Weighted Average Remaining Contractual Life (in years) |  | Weighted Average Exercise Price |  | Options Exercisable |  | Weighted Average Exercise Price
$8.90 – $9.50 |  | 15,938 |  |  | 0.71 |  | $ | 8.90 |  |  | 15,938 |  |  | $ | 8.90 |
$9.51 – $24.00 |  | 51,471 |  |  | 1.71 |  | $ | 9.74 |  |  | 51,471 |  |  | $ | 9.74 |
$24.01 – $25.50 |  | 25,000 |  |  | 6.01 |  | $ | 25.44 |  |  | 25,000 |  |  | $ | 25.44 |
$25.51 - $43.05 |  | 25,000 |  |  | 7.13 |  | $ | 42.35 |  |  | — |  |  | $ | — |
|  | 117,409 |  |  |  |  |  |  | 92,409 |  |  |
Summary of Stock Options Transactions | The following table summarizes information about stock option transactions:
| Options |  | Weighted Average Exercise Price |  | Weighted Average Remaining Contractual Life (in years) |  | Aggregate Intrinsic Value
Balance at January 1, 2017 | 277,224 |  |  | $ | 14.95 |  |  |  |  |
Granted | 25,000 |  |  | 42.35 |  |  |  |  |
Exercised | (42,058 | ) |  | 16.02 |  |  |  |  |
Forfeited | (12,500 | ) |  | 25.44 |  |  |  |  |
Balance at December 31, 2017 | 247,666 |  |  | $ | 17.01 |  |  |  |  |
Exercised | (87,907 | ) |  | 15.75 |  |  |  |  |
Balance at December 31, 2018 | 159,759 |  |  | $ | 17.70 |  |  |  |  |
Exercised | (42,350 | ) |  | 11.57 |  |  |  |  |
Balance at December 31, 2019 | 117,409 |  |  | $ | 19.91 |  |  | 3.64 |  | $ | 3,584,000 |
Summary of Information About Restricted Stock Units and Weighted Average Grant Date Fair Value | The following table summarizes information about non-vested restricted stock units, performance stock units (that will convert to shares upon vesting) and common stock:
| Restricted Stock Units |  | Weighted Average Grant Date Fair Value |  | Common Stock |  | Weighted Average Grant Date Fair Value |  | Performance Stock Units (1) |  | Weighted Average Grant Date Fair Value |  | Deferred Stock Units (2) |  | Weighted Average Grant Date Fair Value
Balance at December 31, 2018 | 395,353 |  |  | $ | 27.61 |  |  | — |  |  | $ | — |  |  | 235,485 |  |  | $ | 33.78 |  |  | 27,243 |  |  | $ | 33.18 |
Granted | 152,972 |  |  | 39.73 |  |  | 7,509 |  |  | 37.95 |  |  | 194,658 |  |  | 40.49 |  |  | 7,509 |  |  | 37.95 |
Vested | (162,690 | ) |  | 24.31 |  |  | (7,509 | ) |  | 37.95 |  |  | (92,696 | ) |  | 28.99 |  |  | — |  |  | — |
Forfeited | (11,203 | ) |  | 35.72 |  |  | — |  |  | — |  |  | (8,190 | ) |  | 46.05 |  |  | — |  |  | — |
Balance at December 31, 2019 | 374,432 |  |  | $ | 33.74 |  |  | — |  |  | $ | — |  |  | 329,257 |  |  | $ | 38.53 |  |  | 34,752 |  |  | $ | 34.21 |
Aggregate Intrinsic Value of Options Exercised and Aggregate Fair Value of Restricted Stock Units and Restricted Shares that Vested | The following table sets forth the aggregate intrinsic value of options exercised and aggregate fair value of restricted stock units and restricted shares that vested during the years ended December 31 (in thousands):
| 2019 |  | 2018 |  | 2017
Aggregate intrinsic value of options exercised | $ | 1,371 |  |  | $ | 2,128 |  |  | $ | 628 |
Aggregate fair value of vested restricted stock units | $ | 10,017 |  |  | $ | 5,307 |  |  | $ | 6,756 |
Aggregate fair value of vested common and restricted shares | $ | 285 |  |  | $ | 149 |  |  | $ | 70 |
Aggregate fair value of vested deferred stock units | $ | 285 |  |  | $ | 369 |  |  | $ | 350 |
Cash Paid to Settle Liability Awards | The following table provides the number of restricted stock units credited to active participant accounts, balance of vested and unvested restricted stock units within active participant accounts, payments made with respect to restricted stock units issued under the MSPP, and MSPP expense during years ended December 31:
| 2019 |  | 2018 |  | 2017
Restricted stock units credited | 61,369 |  |  | 66,843 |  |  | 84,299 |
Restricted stock units balance, vested and unvested | 415,760 |  |  | 387,870 |  |  | 389,189 |
Share-based liabilities paid, in thousands | $ | 6,543 |  |  | $ | 5,232 |  |  | $ | 6,058 |
MSPP expense, in thousands | $ | 2,699 |  |  | $ | 4,809 |  |  | $ | 2,432 |

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