Weighted Average Common Shares - Antidilutive Shares Excluded from Computation of Diluted Shares (Detail) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restricted common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted shares (in shares)	189,000	2,015,659
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted shares (in shares)	1,164,214	4,086,340
Performance share units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of diluted shares (in shares)	36,134	1,296,356