v3.4.0.3
Long-term debt - New Credit Facilities (Details)
CAD in Millions, $ in Millions
1 Months Ended 3 Months Ended 9 Months Ended
May. 02, 2016
CAD
May. 02, 2016
USD ($)
Apr. 13, 2016
CAD
Apr. 13, 2016
USD ($)
Jul. 26, 2015
USD ($)
Apr. 30, 2016
USD ($)
Mar. 31, 2016
CAD
Mar. 31, 2016
USD ($)
Sep. 30, 2015
USD ($)
Sep. 30, 2015
USD ($)
Apr. 13, 2016
USD ($)
Mar. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Long-term debt excluding debentures | Senior unsecured notes, due June 2036 (Cdn$210.0)                          
Debt Instrument [Line Items]                          
Interest rate (as a percent)             5.95%         5.95%  
Long-term debt excluding debentures | Senior unsecured notes due 2018                          
Debt Instrument [Line Items]                          
Interest rate (as a percent)         9.00%                
Aggregate principal amount of debt repurchased         $ 310.9                
Debt Instrument, Repurchase Amount                 $ 330.4 $ 330.4      
Redemption price percentage of principal amount         104.50%                
Long-term debt excluding debentures | Senior unsecured notes due 2018 | Interest expense                          
Debt Instrument [Line Items]                          
Debt Instrument Redemption Applicable Make Whole Premium                   14.0      
Accrued interest paid in redemption of debt                   5.5      
Debt Instrument Write Off of Deferred Financing Cost Related to Repurchase                 $ 9.0 $ 9.0      
Convertible Debentures                          
Debt Instrument [Line Items]                          
Aggregate principal amount of debt                       $ 271.4 $ 277.7
Convertible Debentures | 6.25% Debentures due March 2017                          
Debt Instrument [Line Items]                          
Aggregate principal amount of debt | CAD             CAD 67.2            
Interest rate (as a percent)             6.25%         6.25%  
Convertible Debentures | 6.25% Debentures due March 2017 | Subsequent event                          
Debt Instrument [Line Items]                          
Proceeds deposited with trustee in advance of payment of certain unsecured subordinated debentures | CAD     CAD 67.2                    
Convertible Debentures | 5.6% Debentures due June 2017                          
Debt Instrument [Line Items]                          
Aggregate principal amount of debt | CAD             CAD 75.8            
Interest rate (as a percent)             5.60%         5.60%  
Convertible Debentures | 5.6% Debentures due June 2017 | Subsequent event                          
Debt Instrument [Line Items]                          
Proceeds deposited with trustee in advance of payment of certain unsecured subordinated debentures | CAD     CAD 75.8                    
Convertible Debentures | 5.6% Debentures Due June 2017 And 6.25% Debentures Due March 2017 (Member) | Interest expense | Subsequent event                          
Debt Instrument [Line Items]                          
Write-off of deferred financing costs           $ 1.3              
Convertible Debentures | 5.75% Debentures due June 2019                          
Debt Instrument [Line Items]                          
Interest rate (as a percent)             5.75%         5.75%  
Convertible Debentures | 6.00% Debenture due December 2019                          
Debt Instrument [Line Items]                          
Aggregate principal amount of debt | CAD             CAD 81.0            
Interest rate (as a percent)             6.00%         6.00%  
APLP Holdings | Subsequent event                          
Debt Instrument [Line Items]                          
Amount of cash flow of APLP Holdings and its subsidiaries remaining after application of funds according to the Credit Agreement to be applied under     50               50    
Other percentage of cash flow required to reduce aggregate principal amount of new term loans outstanding to achieve target principal amount that declines     100               100    
APLP Holdings | Subsequent event | Minimum                          
Debt Instrument [Line Items]                          
Leverage ratio as defined in Credit Agreement     4.25               4.25    
Interest coverage ratio as defined in Credit Agreement     2.75               2.75    
APLP Holdings | Subsequent event | Maximum                          
Debt Instrument [Line Items]                          
Leverage ratio as defined in Credit Agreement     6.00               6.00    
Interest coverage ratio as defined in Credit Agreement     4.00               4.00    
APLP Holdings | Interest expense | Subsequent event                          
Debt Instrument [Line Items]                          
Write-off of deferred financing costs           $ 30.0              
APLP Holdings | New Term Loans                          
Debt Instrument [Line Items]                          
Remaining proceeds of New Credit Facility                       $ 105.0  
APLP Holdings | New Term Loans | Subsequent event                          
Debt Instrument [Line Items]                          
Prepayment of term loans if change of control occurs, as a percentage of par     101               101    
Period from initial funding date that APLP would be required to repay, prepay, refinance or replace at a price of 101 percent of the principal amount if they elect to do so for any portion or all of the term loan facilities     1 year 1 year                  
Percent of principal amount required to be repaid, prepaid, refinanced or replaced if APLP elects to do so within one year of initial funding date     101               101    
APLP Holdings | New Credit Facilities | Minimum                          
Debt Instrument [Line Items]                          
Margin on variable interest rate             4.00% 4.00%          
APLP Holdings | New Credit Facilities | New Term Loans | Subsequent event                          
Debt Instrument [Line Items]                          
Aggregate principal amount of debt                     $ 700.0    
Amount drawn under loan                     700.0    
Proceeds from debt, net of discount       $ 679.0                  
Original issue discount (as a percent)     3.00% 3.00%                  
Original issue discount amount                     21.0    
Transaction costs and expenses   $ 14.4                      
APLP Holdings | New Credit Facilities | New Term Loans | Adjusted Eurodollar Rate | Subsequent event                          
Debt Instrument [Line Items]                          
Margin on variable interest rate     5.00% 5.00%                  
APLP Holdings | New Credit Facilities | New Revolver | Subsequent event                          
Debt Instrument [Line Items]                          
Aggregate principal amount of debt                     200.0    
Number of days prior to the Letter of Credit Expiration Date that letters of credit are available to be issued     30 days 30 days                  
Commitment fee related to New Revolver, as a percent     0.75% 0.75%                  
APLP Holdings | New Credit Facilities | Letters of credit | Subsequent event                          
Debt Instrument [Line Items]                          
Aggregate principal amount of debt                     $ 105.8    
Period of debt service covered by debt service reserve fund     6 months 6 months                  
Amount of debt service reserve       $ 25.3                  
APLP Holdings | Convertible Debentures | 6.25% Debentures due March 2017 | Subsequent event                          
Debt Instrument [Line Items]                          
Proceeds deposited with trustee in advance of payment of certain unsecured subordinated debentures | CAD CAD 67.2                        
APLP Holdings | Convertible Debentures | 5.6% Debentures due June 2017 | Subsequent event                          
Debt Instrument [Line Items]                          
Proceeds deposited with trustee in advance of payment of certain unsecured subordinated debentures | CAD CAD 75.8                        
APLP Holdings | Convertible Debentures | 5.6% Debentures Due June 2017 And 6.25% Debentures Due March 2017 (Member)                          
Debt Instrument [Line Items]                          
Proceeds deposited with trustee in advance of payment of certain unsecured subordinated debentures   111.8                      
APLP Holdings | Convertible Debentures | 5.6% Debentures Due June 2017 And 6.25% Debentures Due March 2017 (Member) | Subsequent event                          
Debt Instrument [Line Items]                          
Proceeds deposited with trustee in advance of payment of certain unsecured subordinated debentures       $ 111.8                  
APLP Holdings | Convertible Debentures | 5.75% Debentures due June 2019                          
Debt Instrument [Line Items]                          
Interest rate (as a percent)             5.75%         5.75%  
Amount of subordinated debt that may be repurchased with remaining proceeds               $ 105.3          
APLP Holdings | Convertible Debentures | 6.00% Debenture due December 2019                          
Debt Instrument [Line Items]                          
Interest rate (as a percent)             6.00%         6.00%  
Amount of subordinated debt that may be repurchased with remaining proceeds | CAD             CAD 81.0            
APLP | New Credit Facilities | Maximum                          
Debt Instrument [Line Items]                          
Margin on variable interest rate             5.00% 5.00%          
APLP | Long-term debt excluding debentures | Senior secured term loan, due 2021 | Subsequent event                          
Debt Instrument [Line Items]                          
Redemption of senior secured term loan   $ 447.9                      
APLP | Long-term debt excluding debentures | Senior unsecured notes, due June 2036 (Cdn$210.0) | Subsequent event                          
Debt Instrument [Line Items]                          
Aggregate principal amount of debt | CAD     CAD 210.0                    
Interest rate (as a percent)     5.95%               5.95%    
APLP | Convertible Debentures | 6.25% Debentures due March 2017                          
Debt Instrument [Line Items]                          
Interest rate (as a percent)             6.25%         6.25%  
APLP | Convertible Debentures | 5.6% Debentures due June 2017                          
Debt Instrument [Line Items]                          
Interest rate (as a percent)             5.60%         5.60%