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v3.21.1

Share Based Compensation - Summary of Performance Criteria (Parenthetical) (Detail) - Company | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Abstract] |  |  |  |
Number of companies in peer group | 11 | 12 | 12 | 18

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