v3.4.0.3
Long-term debt (Details)
CAD in Millions, $ in Millions
3 Months Ended
Mar. 31, 2016
CAD
Mar. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
May. 05, 2014
USD ($)
Long-term debt        
Total debt | CAD CAD 210.0      
Current maturities of long-term debt   $ 15.7 $ 15.8  
Total long-term debt   666.9 682.7  
Interest rate swaps        
Long-term debt        
Notional amount   228.9 302.3  
London Interbank Offered Rate (LIBOR) | Interest rate swaps        
Long-term debt        
Notional amount   140.4    
Aggregate principal amount of debt   447.9    
Long-term debt excluding debentures        
Long-term debt        
Total debt   (15.7) (15.8)  
Less: unamortized deferred financing costs   (33.2) (34.8)  
Current maturities of long-term debt   15.7 15.8  
Total long-term debt   666.9 682.7  
Long-term debt excluding debentures | Senior secured term loan, due 2021        
Long-term debt        
Total debt   447.9 473.2  
Current maturities of long-term debt   4.5 4.7  
Long-term debt excluding debentures | Senior unsecured notes, due June 2036 (Cdn$210.0)        
Long-term debt        
Total debt   $ 161.7 151.7  
Interest rate (as a percent) 5.95% 5.95%    
Long-term debt excluding debentures | Epsilon Power Partners term facility, due 2019        
Long-term debt        
Total debt   $ 18.0 19.5  
Current maturities of long-term debt   6.0 6.0  
Long-term debt excluding debentures | Cadillac term loan, due 2025        
Long-term debt        
Total debt   28.9 29.5  
Current maturities of long-term debt   2.6 2.5  
Long-term debt excluding debentures | Piedmont term loan, due 2018        
Long-term debt        
Total debt   59.0 59.0  
Current maturities of long-term debt   2.4 2.4  
Long-term debt excluding debentures | Other long-term debt        
Long-term debt        
Total debt   0.3 0.4  
Current maturities of long-term debt   $ 0.2 $ 0.2  
Long-term debt excluding debentures | Minimum | Other long-term debt        
Long-term debt        
Interest rate (as a percent) 5.50% 5.50%    
Long-term debt excluding debentures | Maximum | Other long-term debt        
Long-term debt        
Interest rate (as a percent) 6.70% 6.70%    
Long-term debt excluding debentures | London Interbank Offered Rate (LIBOR) | Senior secured term loan, due 2021        
Long-term debt        
Minimum percentage of variable rate base 1.00%      
Applicable margin (as a percent) 3.75%      
Long-term debt excluding debentures | London Interbank Offered Rate (LIBOR) | Epsilon Power Partners term facility, due 2019        
Long-term debt        
Applicable margin (as a percent) 3.125%      
Long-term debt excluding debentures | London Interbank Offered Rate (LIBOR) | Cadillac term loan, due 2025        
Long-term debt        
Applicable margin (as a percent) 1.37%      
Long-term debt excluding debentures | London Interbank Offered Rate (LIBOR) | Piedmont term loan, due 2018        
Long-term debt        
Applicable margin (as a percent) 3.50%      
Long-term debt excluding debentures | London Interbank Offered Rate (LIBOR) | Interest rate swaps | Senior secured term loan, due 2021        
Long-term debt        
Notional amount   $ 140.4   $ 199.0
Aggregate principal amount of debt       $ 600.0