Annual report pursuant to Section 13 and 15(d)

Debt - Narrative (Details)

v3.20.2
Debt - Narrative (Details)
1 Months Ended 12 Months Ended
Sep. 30, 2020
USD ($)
Sep. 30, 2020
USD ($)
Sep. 30, 2019
USD ($)
Sep. 30, 2018
USD ($)
Sep. 30, 2020
AUD ($)
Debt Instrument [Line Items]          
Current portion of long-term debt and other borrowings $ 10,878,000 $ 10,878,000 $ 9,658,000    
Outstanding borrowings 5,000,000.0 5,000,000.0 3,200,000    
Interest paid   $ 1,600,000 $ 2,500,000 $ 600,000  
Credit Agreement          
Debt Instrument [Line Items]          
Leverage ratio   2.50      
Debt instrument, covenant, actual consolidated leverage ratio (less than)   1.0      
Credit Agreement | Revolving Credit Facility | Line of Credit          
Debt Instrument [Line Items]          
Maximum borrowing capacity 400,000,000 $ 400,000,000      
Borrowings 0 0      
Credit Agreement | Swingline | Line of Credit          
Debt Instrument [Line Items]          
Maximum borrowing capacity 5,000,000 5,000,000      
Credit Agreement | Letters of credit | Line of Credit          
Debt Instrument [Line Items]          
Maximum borrowing capacity $ 50,000,000 $ 50,000,000      
Credit Agreement | Minimum          
Debt Instrument [Line Items]          
Line of credit facility, unused capacity, commitment fee percentage   0.125%      
Credit Agreement | Minimum | Base Rate          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent)   0.00%      
Credit Agreement | Minimum | Eurocurrency Rate          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent)   1.00%      
Credit Agreement | Minimum | Index Rate          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent)   1.00%      
Credit Agreement | Maximum          
Debt Instrument [Line Items]          
Line of credit facility, unused capacity, commitment fee percentage   0.275%      
Credit Agreement | Maximum | Base Rate          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent)   0.75%      
Credit Agreement | Maximum | Eurocurrency Rate          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent)   1.75%      
Credit Agreement | Maximum | Index Rate          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent)   1.75%      
Australian Term Facility Agreement | Secured Debt          
Debt Instrument [Line Items]          
Line of credit facility, unused capacity, commitment fee percentage 0.80%        
Debt instrument, face amount         $ 65,000,000
Outstanding borrowings $ 21,400,000 $ 21,400,000      
Current portion of long-term debt and other borrowings $ 3,600,000 3,600,000      
Minimum liquidity         $ 25,000,000
Australian Term Facility Agreement | Australian Bank Bill Swap Bid Rate | Secured Debt          
Debt Instrument [Line Items]          
Basis spread on variable rate (as a percent) 2.00%        
Canada And United Kingdom Facility | Line of Credit          
Debt Instrument [Line Items]          
Borrowings $ 7,000,000.0 $ 7,000,000.0