Earnings Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
2016 VSEP [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase common shares not included in the computation of diluted EPS	0
Restricted Stock Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase common shares not included in the computation of diluted EPS	700,000	700,000	300,000
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase common shares not included in the computation of diluted EPS	300,000		600,000
Options to purchase common shares included in the computation of diluted EPS		400,000