Earnings Per Share - Schedule of Computations of Weighted Average Shares Outstanding (Non-Printing) (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share Based Awards
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Potentially dilutive restricted share awards excluded from computation of diluted EPS (in shares)	0.4	0.3	0.4	0.6