Quarterly report pursuant to Section 13 or 15(d)

Significant Accounting Policies - Revenue by Major Customers (Detail)

v3.19.3.a.u2
Significant Accounting Policies - Revenue by Major Customers (Detail) - Revenues - Customer Concentration Risk
3 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Private    
Concentration Risk [Line Items]    
Concentration risk percentage 39.40% 32.10%
Public    
Concentration Risk [Line Items]    
Concentration risk percentage 60.60% 67.90%