XML 40 R61.htm IDEA: XBRL DOCUMENT v3.19.3
Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Net proceeds from issuance of common stock under incentive compensation and employee purchase plans $ 2,412 $ 7,683 $ 3,158