XML 32 R20.htm IDEA: XBRL DOCUMENT v3.8.0.1
Earnings Per Share - Weighted-Average Number of Shares of Common Stock Used to Calculate Basic and Diluted Earnings Per Share (Detail) - shares
shares in Thousands
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Earnings Per Share [Abstract]    
Weighted-average number of shares of common stock for calculating basic earnings per share 24,067 23,950
Effect of potentially dilutive securities from equity-based compensation 411 282
Weighted-average number of shares of common stock for calculating diluted earnings per share 24,478 24,232