Earnings Per Share - Number of Potential Common Shares that have been Excluded from Computation of Diluted Earnings Per Share for Indicated Period Due to Their Anti-Dilutive Nature (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Potential common shares	1,082	1,233	1,082	1,233