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Accounting for Stock-based Compensation - Additional Information (Details) $ / shares in Units, $ in Millions |  | 12 Months Ended
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Apr. 04, 2018 shares | Dec. 31, 2020 USD ($) PerformancePeriod $ / shares shares | Dec. 31, 2019 USD ($) PerformancePeriod shares | Dec. 31, 2018 USD ($) shares | Dec. 31, 2017 PerformancePeriod shares | Dec. 31, 2015 PerformancePeriod
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, options, outstanding, weighted average remaining contractual term |  | 3 years 9 months 18 days |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting period |  | 3 years |  |  |  |
Share-based compensation arrangement by share-based payment award, options, vested and expected to vest, exercisable, weighted average remaining contractual term |  | 2 years 3 months 18 days |  |  |  |
Share-based compensation arrangement by share-based payment award, options, exercisable, weighted average remaining contractual term |  | 2 years 3 months 18 days |  |  |  |
Employee Stock Option |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, number of shares grants |  | 0 | 0 | 0 |  |
Share-based compensation arrangement by share-based payment award, options, outstanding, weighted average remaining contractual term |  | 10 years |  |  |  |
Share price | $ / shares |  | $ 74.33 |  |  |  |
Share-based compensation arrangement by share-based payment award, options, exercises in period, intrinsic value | $ |  | $ 5.1 | $ 4.9 | $ 8.3 |  |
Restricted Stock Units (RSUs) |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share price | $ / shares |  | $ 74.33 |  |  |  |
Share-based compensation arrangement by share-based payment award, equity instruments other than options, vested in period, fair value | $ |  | $ 14.1 | $ 7.2 | $ 6.5 |  |
Number of shares, granted |  | 170,411 | 159,831 | 235,480 |  |
Number of shares, vested |  | 258,307 | 164,913 | 169,279 |  |
Cash Settled RSUs |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share price | $ / shares |  | $ 74.33 |  |  |  |
Share-based compensation arrangement by share-based payment award, equity instruments other than options, vested in period, fair value | $ |  | $ 9.3 | $ 7.2 | $ 7.7 |  |
Number of shares, granted |  | 134,259 | 103,606 | 147,103 |  |
Number of shares, vested |  | 154,653 | 123,395 | 147,759 |  |
Non-Employee Director Awards |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Number of shares, granted |  |  |  | 7,985 |  |
Performance Shares |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share price | $ / shares |  | $ 74.33 |  |  |  |
Number of performance period in performance based share program | PerformancePeriod |  | 1 | 2 |  | 3 | 2
Percentage of multiplication award by product |  | 2.00% |  |  |  |
Number of shares, granted |  | 87,314 | 85,928 | 45,136 | 88,038 |
Number of shares, vested |  | 88,038 | 107,000 | 30,576 |  |
Number of shares, granted, adjusted for partial performance periods |  |  |  |  | 94,178 |
Number of shares, expected to vest |  | 94,178 |  |  |  |
Minimum |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, fair value assumptions, expected forfeiture rate |  | 0.00% |  |  |  |
Minimum | Employee Stock Option |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting period |  | 3 years |  |  |  |
Minimum | Restricted Stock Units (RSUs) |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting period |  | 3 years |  |  |  |
Minimum | Cash Settled RSUs |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting period |  | 3 years |  |  |  |
Maximum |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, fair value assumptions, expected forfeiture rate |  | 17.75% |  |  |  |
Maximum | Employee Stock Option |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting period |  | 4 years |  |  |  |
Maximum | Restricted Stock Units (RSUs) |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting period |  | 4 years |  |  |  |
Maximum | Cash Settled RSUs |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, award vesting period |  | 4 years |  |  |  |
Omnibus Plan |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share-based compensation arrangement by share-based payment award, number of shares grants | 1,600,000 | 90,742 |  |  |  |
Share-based compensation arrangement by share-based payment award, number of additional awards |  | 0 |  |  |  |
Share-based compensation arrangement by share-based payment award, number of shares available for grant |  | 1,107,968 |  |  |  |
Share-based compensation arrangement by share-based payment award, options, outstanding, weighted average remaining contractual term |  | 10 years |  |  |  |
Omnibus Plan | Non-Employee Director Awards |  |  |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |  |  |  |  |
Share price | $ / shares |  | $ 74.33 |  |  |  |
Number of shares, granted |  | 12,541 | 9,732 | 11,606 |  |
Number of shares, vested |  | 10,891 | 9,840 | 5,395 |  |

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