v3.5.0.2
Long-term debt - New Credit Facilities (Details)
CAD in Millions, $ in Millions
1 Months Ended 3 Months Ended 9 Months Ended
Jul. 26, 2016
USD ($)
Apr. 13, 2016
USD ($)
Jul. 26, 2015
USD ($)
Jul. 31, 2016
USD ($)
Apr. 30, 2016
USD ($)
Sep. 30, 2016
USD ($)
Jun. 30, 2016
CAD
Jun. 30, 2016
USD ($)
Sep. 30, 2015
USD ($)
Sep. 30, 2016
USD ($)
Sep. 30, 2015
USD ($)
Jul. 22, 2016
USD ($)
Jun. 17, 2016
Apr. 13, 2016
CAD
Apr. 13, 2016
USD ($)
Dec. 31, 2015
USD ($)
Debt Instrument [Line Items]                                
Original issue discount amount           $ 18.5       $ 18.5            
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]                                
Redemption price percentage of principal amount     104.50%                          
Debt Instrument, Repurchase Amount $ 330.4                              
Interest rate (as a percent)     9.00%                          
Aggregate principal amount of debt repurchased     $ 310.9                          
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           $ 101.4       $ 101.4           $ 277.7
Convertible Debentures | 6.25% Debentures due March 2017                                
Debt Instrument [Line Items]                                
Interest rate (as a percent)           6.25%       6.25%            
Convertible Debentures | 5.6% Debentures due June 2017                                
Debt Instrument [Line Items]                                
Interest rate (as a percent)           5.60%       5.60%       5.60% 5.60%  
Convertible Debentures | 5.6% Debentures Due June 2017 And 6.25% Debentures Due March 2017 (Member) | Interest expense                                
Debt Instrument [Line Items]                                
Write-off of deferred financing costs         $ 1.3                      
Convertible Debentures | 5.75% Debentures due June 2019                                
Debt Instrument [Line Items]                                
Redemption price percentage of principal amount             965.00% 965.00%                
Debt Instrument, Repurchase Amount               $ 62.7       $ 62.7        
Interest rate (as a percent)           5.75%   5.75%   5.75%     5.75%      
Convertible Debentures | 5.75% Debentures due June 2019 | Interest expense                                
Debt Instrument [Line Items]                                
Write-off of deferred financing costs       $ 1.4                        
APLP Holdings                                
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  
APLP Holdings | 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 | 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  
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 | Interest expense                                
Debt Instrument [Line Items]                                
Write-off of deferred financing costs           $ 30.2                    
APLP Holdings | New Term Loans                                
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                            
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%            
APLP Holdings | New Credit Facilities | New Term Loans                                
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%                            
Original issue discount amount           $ 21.0       $ 21.0            
Transaction costs and expenses               $ 14.4                
APLP Holdings | New Credit Facilities | New Term Loans | Adjusted Eurodollar Rate                                
Debt Instrument [Line Items]                                
Margin on variable interest rate   5.00%                            
APLP Holdings | New Credit Facilities | New Revolver                                
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                            
Commitment fee related to New Revolver, as a percent   0.75%                            
APLP Holdings | New Credit Facilities | Letters of credit                                
Debt Instrument [Line Items]                                
Aggregate principal amount of debt                             $ 105.8  
Period of debt service covered by debt service reserve fund   6 months                            
Amount of debt service reserve   $ 25.3                            
APLP Holdings | Convertible Debentures | 6.25% Debentures due March 2017                                
Debt Instrument [Line Items]                                
Redemption of convertible unsecured subordinated debentures | CAD             CAD 67.2                  
APLP Holdings | Convertible Debentures | 5.6% Debentures due June 2017                                
Debt Instrument [Line Items]                                
Redemption of convertible 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]                                
Redemption of convertible unsecured subordinated debentures               110.7                
APLP | New Credit Facilities | Maximum                                
Debt Instrument [Line Items]                                
Margin on variable interest rate                   5.00%            
APLP | Long-term debt excluding debentures | Senior secured term loan facility, due 2021                                
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)                                
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%                
APLP | Convertible Debentures | 5.6% Debentures due June 2017                                
Debt Instrument [Line Items]                                
Interest rate (as a percent)               5.60%