Quarterly report pursuant to Section 13 or 15(d)

Financing Agreements - Narrative (Details)

v3.4.0.3
Financing Agreements - Narrative (Details)
3 Months Ended 6 Months Ended
Mar. 31, 2016
USD ($)
Mar. 31, 2015
Mar. 31, 2016
USD ($)
Mar. 31, 2015
Mar. 24, 2016
USD ($)
Sep. 30, 2015
USD ($)
Dec. 31, 2014
USD ($)
Dec. 19, 2014
USD ($)
Dec. 15, 2014
USD ($)
Debt instrument [Line Items]                  
Total debt $ 712,000,000   $ 712,000,000     $ 528,100,000      
Maximum ratio of Indebtedness to EBITDA allowed     3.5            
Minimum ratio of EBITDA to interest expense allowed     3.5            
Restricted cash and cash equivalent 800,000   $ 800,000     800,000      
$700 revolving credit facility (excluding outstanding letters of credit)                  
Debt instrument [Line Items]                  
Total debt 295,600,000   295,600,000     107,600,000      
Line of credit facility, maximum borrowing capacity 282,600,000   282,600,000         $ 700.0  
Letters of credit outstanding, amount 10,600,000   10,600,000            
Line of credit facility, remaining borrowing capacity $ 393,800,000   $ 393,800,000            
Weighted average interest rates 1.46% 1.30% 1.35% 1.29%          
Weighted average facility fee 0.21% 0.23% 0.19% 0.24%          
Term loan                  
Debt instrument [Line Items]                  
Total debt $ 166,500,000   $ 166,500,000     171,000,000      
Debt instrument, face amount               $ 180.0  
Weighted average interest rates 1.76% 1.55% 1.61% 1.54%          
Other financing agreements                  
Debt instrument [Line Items]                  
Line of credit facility, maximum borrowing capacity $ 219,900,000   $ 219,900,000            
Line of credit facility, amount utilized for bank guarantees 124,800,000   124,800,000            
$100 Series A Notes                  
Debt instrument [Line Items]                  
Total debt 100,000,000   100,000,000     $ 100,000,000      
Stated interest rate                 4.60%
Debt instrument, face amount 100,000,000   100,000,000       $ 100,000,000   $ 100.0
Private Shelf Facility, Accordion Feature, Maximum         $ 200.0       $ 150.0
Syndicated credit facility                  
Debt instrument [Line Items]                  
Line of credit facility, maximum borrowing capacity 150,000,000   150,000,000            
Interest Rate Swap [Member] | Cash flow hedging                  
Debt instrument [Line Items]                  
Derivative, notional amount $ 0   $ 0