Net Earnings Per Share ("EPS") - Reconciliation of Denominators of Basic and Diluted EPS Calculations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net earnings	$ 33,961	$ 39,327
Denominator:
Weighted average shares used to compute basic EPS	35,233	35,609
Dilutive potential common shares due to dilutive RSUs, net of tax effect	413	494
Weighted average shares used to compute diluted EPS	35,646	36,103
Net earnings per share:
Basic	$ 0.96	$ 1.10
Diluted	$ 0.95	$ 1.09