XML 114 R96.htm IDEA: XBRL DOCUMENT v3.8.0.1
Earnings Per Share - Summary of Reconciliation of Numerators and Denominators Used in Basic and Diluted Per Share Computations (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Class A Common Stock [Member]                      
Basic and diluted earnings per share:                      
Allocation of net income                 $ 5,879 $ 24,885 $ 17,155
Number of shares used in basic computation                 21,799 20,917 22,046
Weighted-average effect of dilutive securities                      
Add: Director and employee stock options                 843 613 348
Number of shares used in per share computations                 22,642 21,530 22,394
Weighted-average shares outstanding                 21,799 20,917 22,046
Numerator:                      
Allocation of net income                 $ 5,879 $ 24,885 $ 17,155
Denominator:                      
Weighted-average shares outstanding                 21,799 20,917 22,046
Basic earnings per share $ (0.10) $ 0.27 $ (0.09) $ 0.19 $ 0.21 $ 0.19 $ 0.33 $ 0.46 $ 0.27 $ 1.19 $ 0.78
Denominator:                      
Diluted earnings per share (0.10) 0.26 (0.08) 0.18 0.20 0.18 0.32 0.46 $ 0.26 $ 1.16 $ 0.77
Class B Common Stock [Member]                      
Basic and diluted earnings per share:                      
Allocation of net income                 $ 1,237 $ 5,916 $ 3,835
Number of shares used in basic computation                 5,577 5,577 5,577
Weighted-average effect of dilutive securities                      
Weighted-average shares outstanding                 5,577 5,577 5,577
Basic and diluted earnings per share $ (0.11) $ 0.24 $ (0.08) $ 0.17 $ 0.18 $ 0.16 $ 0.30 $ 0.42 $ 0.22 $ 1.06 $ 0.69
Denominator:                      
Weighted-average shares outstanding                 5,577 5,577 5,577
Basic earnings per share                 $ 0.22 $ 1.06 $ 0.69
Denominator:                      
Diluted earnings per share                 $ 0.22 $ 1.06 $ 0.69