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Stock-Based Compensation - Summarizes Information of Performance Share Awards (Detail) - Performance Awards
12 Months Ended
Dec. 31, 2019
$ / shares
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Non-vested at December 31, 2018 | shares 409,091
Granted | shares 310,471
Vested | shares (126,700)
Forfeited | shares (37,205)
Non-vested at December 31, 2019 | shares 555,657
Non-vested at December 31, 2018 | $ / shares $ 57.50
Granted | $ / shares 47.77
Vested | $ / shares 50.85
Forfeited | $ / shares 55.74
Non-vested at December 31, 2019 | $ / shares $ 53.71