v3.8.0.1
Earnings Per Share - Computation of Basic and Diluted Net Earnings (Loss) Per Share (Detail) - USD ($)
shares in Thousands, $ in Thousands
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Numerator:    
Net income $ 11,353 $ 13,632
Denominator:    
Denominator for basic earnings per share – weighted average shares (in shares) 20,835 20,738
Effect of dilutive securities:    
Employee stock options (in shares) 76 96
Denominator for diluted earnings per share - weighted average shares (in shares) 20,911 20,834