XML 77 R63.htm IDEA: XBRL DOCUMENT v3.8.0.1
Net Income Per Share - Basic and Diluted Net Income Per Share (Detail) - shares
3 Months Ended 12 Months Ended
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2015
Earnings Per Share [Abstract]                      
Weighted average common shares outstanding used in calculating basic income per share                 23,966,611 24,203,947 24,466,243
Effect of dilutive options and non-vested restricted stock awards                 712,189 616,900 636,046
Weighted average common and common equivalent shares used in calculating diluted income per share 23,591,854 25,095,398 25,116,359 24,923,125 25,010,193 24,770,980 24,758,826 24,742,330 24,678,800 24,820,847 25,102,289