Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Details)

v3.5.0.2
Fair Value Measurements (Details) - USD ($)
$ in Millions
12 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Dec. 15, 2014
Jul. 09, 2010
Liabilities:        
Long-term Debt $ 610.1 $ 528.1    
Additional disclosures        
Stated interest rate 5.50%      
$150 senior unsecured notes        
Liabilities:        
Long-term Debt $ 149.3 149.1    
Additional disclosures        
Term of debt issued 10 years      
Stated interest rate 5.50%     5.50%
$100 Series A Notes        
Liabilities:        
Long-term Debt $ 100.0 100.0    
Additional disclosures        
Stated interest rate     4.60%  
Level 1        
Assets:        
Cash and cash equivalents 52.0 48.3    
Investments in rabbi trust 4.0 4.6    
Derivative instruments 0.0 0.0    
Liabilities:        
Revolving credit facilities 0.0 0.0    
Term loan 0.0 0.0    
Derivative instruments 0.0 0.0    
Level 1 | $150 senior unsecured notes        
Liabilities:        
Senior notes 163.5 165.0    
Level 1 | $100 Series A Notes        
Liabilities:        
Long-term Debt 0.0 0.0    
Level 2        
Assets:        
Cash and cash equivalents 0.0 0.0    
Investments in rabbi trust 0.0 0.0    
Derivative instruments 1.4 1.1    
Liabilities:        
Revolving credit facilities 198.5 107.6    
Term loan 162.0 171.0    
Derivative instruments 3.3 5.8    
Level 2 | $150 senior unsecured notes        
Liabilities:        
Senior notes 0.0 0.0    
Level 2 | $100 Series A Notes        
Liabilities:        
Long-term Debt 110.8 100.6    
Level 3        
Assets:        
Cash and cash equivalents 0.0 0.0    
Investments in rabbi trust 0.0 0.0    
Derivative instruments 0.0 0.0    
Liabilities:        
Revolving credit facilities 0.0 0.0    
Term loan 0.0 0.0    
Derivative instruments 0.0 0.0    
Level 3 | $150 senior unsecured notes        
Liabilities:        
Senior notes 0.0 0.0    
Level 3 | $100 Series A Notes        
Liabilities:        
Long-term Debt 0.0 0.0    
Carrying Value        
Assets:        
Cash and cash equivalents 52.0 48.3    
Investments in rabbi trust 4.0 4.6    
Derivative instruments 1.4 1.1    
Liabilities:        
Revolving credit facilities 198.5 107.6    
Term loan 162.0 171.0    
Derivative instruments 3.3 5.8    
Additional disclosures        
Carrying amount of private equity limited partnerships for which fair value is not readily available 7.6 8.3    
Carrying Value | $150 senior unsecured notes        
Liabilities:        
Senior notes $ 149.3 $ 149.1