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Stock-Based Compensation, Stock Award and Incentive Plan and Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Employee service share-based compensation, aggregate disclosures [Abstract] |  |  |
Number of common stock available for issuance (in shares) | 880,000 |  |
Term of stock options granted under Plan | 10 years |  |
Vesting period, generally, for stock options granted under the plan | 3 years |  |
Share based compensation costs | $ 8.1 | $ 6.2 | $ 8.1
Stock Options [Member] |  |  |
Employee service share-based compensation, aggregate disclosures [Abstract] |  |  |
Share based compensation costs | 4.8 | 4.2 | 4.1
Tax benefit of share-based compensation | $ 1.3 | $ 1.1 | $ 1.1
Forfeiture rate assumed | 8.85% | 8.20% | 8.71%
Weighted average grant date fair value for stock options granted (in dollars per share) | $ 18.86 | $ 25.79 | $ 30.28
Weighted average grant date fair value for stock options vested (in dollars per share) | $ 22.46 | $ 21.33 | $ 18.45
Total intrinsic value of stock options exercised | $ 2.2 | $ 3.3 | $ 11.7
Weighted Average Assumptions [Abstract] |  |  |
Expected life | 6 years 7 months 6 days | 6 years 2 months 12 days | 6 years 4 months 24 days
Interest rate | 2.62% | 2.50% | 2.04%
Volatility | 30.26% | 30.33% | 36.61%
Expected dividend yield | 0.37% | 0.26% | 0.26%
Stock Options [Roll Forward] |  |  |
Balance, beginning of year (in shares) | 1,054,259 |  |
Granted (in shares) | 271,261 |  |
Exercised (in shares) | (79,686) |  |
Canceled (in shares) | (14,214) |  |
Expired | (4,000) |  |
Balance, end of year (in shares) | 1,227,620 | 1,054,259 |
Exercisable, end of year (in shares) | 788,847 |  |
Weighted Average Exercise Price Per Share [Abstract] |  |  |
Balance, beginning of year (in dollars per share) | $ 54.04 |  |
Granted (in dollars per share) | 54.44 |  |
Exercised (in dollars per share) | 27.26 |  |
Canceled (in dollars per share) | 66.93 |  |
Expired (in dollars per share) | 19.86 |  |
Balance, end of year (in dollars per share) | 55.83 | $ 54.04 |
Exercisable, end of year (in dollars per share) | $ 51.75 |  |
Weighted Average Remaining Contractual Life [Abstract] |  |  |
Outstanding options, end of year | 6 years 2 months 12 days |  |
Exercisable options, end of year | 4 years 10 months 24 days |  |
Aggregate Intrinsic Value [Abstract] |  |  |
Outstanding options, end of year | $ 9.2 |  |
Exercisable options, end of year | $ 8.3 |  |
Additional Information [Abstract] |  |  |
Closing stock price on last business day of the period (in dollars per share) | $ 57.63 |  |
Weighted average intrinsic value of options exercised (in dollars per share) | $ 27.21 | $ 33.10 | $ 32.95
Unrecognized stock-based compensation expense | $ 4.6 |  |
Weighted average period over which unrecognized stock-based compensation expense is expected to be recognized | 3 years |  |
Nonvested Stock Options [Member] |  |  |
Stock Options [Roll Forward] |  |  |
Balance, beginning of year (in shares) | 365,607 |  |
Granted (in shares) | 271,261 |  |
Vested (in shares) | (189,854) |  |
Canceled (in shares) | (8,241) |  |
Balance, end of year (in shares) | 438,773 | 365,607 |
Weighted Average Exercise Price Per Share [Abstract] |  |  |
Balance, beginning of year (in dollars per share) | $ 68.86 |  |
Granted (in dollars per share) | 54.44 |  |
Vested (in dollars per share) | 61.64 |  |
Canceled (in dollars per share) | 64.19 |  |
Balance, end of year (in dollars per share) | $ 63.15 | $ 68.86 |

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