XML 111 R41.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Summary of Significant Accounting Policies - Short-term Investments (Details)
Sep. 30, 2019
Sep. 30, 2018
Minimum    
Short-term Debt [Line Items]    
Interest rate 1.97% 1.97%
Maximum    
Short-term Debt [Line Items]    
Interest rate 2.80% 2.80%