Quarterly report pursuant to Section 13 or 15(d)

Debt - Additional Information (Details)

v3.5.0.2
Debt - Additional Information (Details)
3 Months Ended 9 Months Ended
Jun. 30, 2017
USD ($)
Jun. 30, 2016
USD ($)
Apr. 16, 2012
USD ($)
May 31, 2016
USD ($)
May 31, 2016
USD ($)
Debt Instrument [Line Items]          
Senior credit facility expansion option, available       $ 450,000,000 $ 450,000,000
Debt Instrument, actual interest rate       2.44% 2.44%
Libor Rate          
Debt Instrument [Line Items]          
Debt instrument, interest rate over variable rate       2.00%  
Revolving Credit Facility          
Debt Instrument [Line Items]          
Debt Instrument, Maturity Date         May 08, 2020
Maximum borrowing capacity       $ 600,000,000 $ 600,000,000
Senior Credit Facility - Term Loan          
Debt Instrument [Line Items]          
Maximum borrowing capacity       300,000,000 300,000,000
Line of Credit | Senior Credit Facility - Revolver          
Debt Instrument [Line Items]          
Unused credit line       592,100,000 592,100,000
Unused credit line Available for Borrowing, Amount       $ 183,000,000 $ 183,000,000
Senior Notes | 5.625% Senior Notes          
Debt Instrument [Line Items]          
Debt Instrument, Maturity Date         Jun. 15, 2022
Debt Instrument, Face Amount     $ 300,000,000    
Debt instrument, interest rate     5.625%    
Minimum          
Debt Instrument [Line Items]          
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage       0.15%  
Interest coverage ratio       3.5 3.5
Minimum | Libor Rate          
Debt Instrument [Line Items]          
Debt instrument, interest rate over variable rate       1.00%  
Minimum | Base Rate          
Debt Instrument [Line Items]          
Debt instrument, interest rate over variable rate       0.00%  
Minimum | Senior Notes | 5.625% Senior Notes          
Debt Instrument [Line Items]          
Debt Instrument, Redemption Price, Percentage     100.00%    
Maximum          
Debt Instrument [Line Items]          
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage       0.35%  
Leverage ratio       3.75 3.75
Maximum | Libor Rate          
Debt Instrument [Line Items]          
Debt instrument, interest rate over variable rate       2.25%  
Maximum | Base Rate          
Debt Instrument [Line Items]          
Debt instrument, interest rate over variable rate       1.25%  
Maximum | Senior Notes | 5.625% Senior Notes          
Debt Instrument [Line Items]          
Debt Instrument, Redemption Price, Percentage     102.80%    
Starting on June 30, 2016 | Scenario, Forecast | Senior Credit Facility - Term Loan          
Debt Instrument [Line Items]          
Quarterly installments, payable on term loan   $ 3,750,000      
Starting on June 30, 2017 | Scenario, Forecast | Senior Credit Facility - Term Loan          
Debt Instrument [Line Items]          
Quarterly installments, payable on term loan $ 7,500,000