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, 2021	Mar. 31, 2020
Numerator:
Net earnings	$ 43,168	$ 33,961
Denominator:
Weighted average shares used to compute basic EPS	35,199	35,233
Dilutive potential common shares due to dilutive RSUs, net of tax effect	461	413
Weighted average shares used to compute diluted EPS	36,699	35,646
Net earnings per share:
Basic	$ 1.23	$ 0.96
Diluted	$ 1.18	$ 0.95
Notes [Member]
Denominator:
Dilutive potential common shares due to the Notes	1,039