XML 62 R52.htm IDEA: XBRL DOCUMENT v3.7.0.1
Debt - Narrative (Details)
3 Months Ended 9 Months Ended
Mar. 31, 2017
USD ($)
Mar. 31, 2016
USD ($)
Mar. 31, 2017
USD ($)
Mar. 31, 2016
USD ($)
Jun. 30, 2016
USD ($)
Debt Instrument [Line Items]          
Short-term borrowings $ 14,200,000   $ 14,200,000   $ 0
Interest costs 8,000,000 $ 7,600,000 23,400,000 $ 22,300,000  
Interest costs, capitalized 300,000 $ 400,000 900,000 $ 1,500,000  
Credit Agreement          
Debt Instrument [Line Items]          
Maximum borrowing capacity 400,000,000   400,000,000    
Debt issuance costs 1,400,000   1,400,000    
Letters of credit issued 5,800,000   5,800,000    
Short-term borrowings 14,200,000   14,200,000    
Credit Agreement available for future borrowings $ 380,000,000   $ 380,000,000    
Credit Agreement | LIBOR          
Debt Instrument [Line Items]          
Debt Instrument, Description of Variable Rate Basis     LIBOR    
Interest rate margin     1.50%    
Credit Agreement | LIBOR | Minimum          
Debt Instrument [Line Items]          
Interest rate margin     1.00%    
Credit Agreement | LIBOR | Maximum          
Debt Instrument [Line Items]          
Interest rate margin     1.75%    
Credit Agreement | Base Rate          
Debt Instrument [Line Items]          
Debt Instrument, Description of Variable Rate Basis     Base Rate    
Interest rate margin     0.50%    
Credit Agreement | Base Rate | Minimum          
Debt Instrument [Line Items]          
Interest rate margin     0.00%    
Credit Agreement | Base Rate | Maximum          
Debt Instrument [Line Items]          
Interest rate margin     0.75%    
Letters of credit          
Debt Instrument [Line Items]          
Commitment fee rate     0.275%    
Letter of credit fees     1.50%    
Required interest coverage ratio     3.50    
Letters of credit | Minimum          
Debt Instrument [Line Items]          
Commitment fee rate     0.125%    
Letter of credit fees     1.00%    
Letters of credit | Maximum          
Debt Instrument [Line Items]          
Commitment fee rate     0.40%    
Letter of credit fees     1.75%    
Required debt to capital ratio (less than 55%) 0.55   0.55