Quarterly report pursuant to Section 13 or 15(d)

Debt (Details)

v3.5.0.2
Debt (Details)
CAD in Millions
9 Months Ended
Jun. 30, 2016
USD ($)
period
letter_of_credit
Jun. 30, 2015
USD ($)
Jun. 30, 2016
CAD
period
letter_of_credit
Mar. 09, 2015
USD ($)
Debt Instrument [Line Items]        
Long-term Debt $ 69,000,000      
Credit Agreement Expiring January 2020        
Debt Instrument [Line Items]        
Maximum borrowing capacity       $ 400,000,000
Dividend payment restriction ratio (less than) 2.5      
Total leverage ratio (less than) 1      
Interest paid $ 2,900,000 $ 500,000    
Credit Agreement Expiring January 2020 | U.S Dollar Borrowings        
Debt Instrument [Line Items]        
Amount borrowed 207,500,000      
Credit Agreement Expiring January 2020 | Canadian Dollar Borrowings        
Debt Instrument [Line Items]        
Amount borrowed $ 2,500,000   CAD 3.3  
Credit Agreement Expiring January 2020 | Maximum        
Debt Instrument [Line Items]        
Leverage ratio 2.5      
Swingline Loans        
Debt Instrument [Line Items]        
Maximum borrowing capacity       5,000,000
Letters of Credit        
Debt Instrument [Line Items]        
Maximum borrowing capacity       $ 30,000,000
Number of letters of credit issued | letter_of_credit 3   3  
Outstanding borrowings $ 5,200,000      
Atlantic Innovation Fund of Canada        
Debt Instrument [Line Items]        
Amount borrowed 800,000   CAD 1.1  
Interest expense, debt $ 0      
Number of remaining quarterly installments | period 24   24  
Letters of Credit (Other than Revolving Credit Agreement)        
Debt Instrument [Line Items]        
Number of letters of credit issued | letter_of_credit 2   2  
Outstanding borrowings $ 3,000,000