XML 147 R120.htm IDEA: XBRL DOCUMENT v3.21.1
Financial instruments - Additional Information (Detail)
 1 Months Ended 12 Months Ended
Nov. 30, 2020
USD ($)
termLoanFacility
derivativeContract
Dec. 31, 2020
USD ($)
$ / MWh
MWh
Dec. 31, 2019
USD ($)
Dec. 31, 2020
CAD ($)
$ / MWh
Jul. 17, 2020
USD ($)
Jul. 17, 2020
CAD ($)
Dec. 31, 2019
CAD ($)
Sep. 30, 2019
USD ($)
instrument
May 23, 2019
USD ($)
Derivative [Line Items]                  
Number of term loan facilities | termLoanFacility 2                
Number of pay-variable and receive-fixed interest rate swaps | instrument               3  
Foreign currency gain (loss)   $ 28,406,000 $ 7,795,000            
Revenue collection period   45 days              
Cash on hand   $ 101,614,000              
Available to be drawn on senior debt facilities   $ 2,675,735,000              
Accounts Receivable | Credit Concentration Risk                  
Derivative [Line Items]                  
Percentage of revenue contributed by large utility customers   91.00%              
Ascendant                  
Derivative [Line Items]                  
Number of interest rate swaps redesignated as cash flow hedges | derivativeContract 2                
Liberty Power Group                  
Derivative [Line Items]                  
Foreign currency gain (loss)   $ (18,875,000) $ (15,946,000)            
Bonds                  
Derivative [Line Items]                  
Debt instrument, term     10 years            
Senior Unsecured Notes | Senior Unsecured Notes Due January 2029                  
Derivative [Line Items]                  
Debt instrument, term     10 years            
Senior Unsecured Notes | U.S. Dollar Subordinated Unsecured Notes                  
Derivative [Line Items]                  
Interest rate (percent)     6.20%       6.20%    
Par value   637,500,000 $ 350,000,000           $ 350,000,000
Interest rate swaps | U.S. Dollar Subordinated Unsecured Notes                  
Derivative [Line Items]                  
Derivative notional amount               $ 350,000,000  
Interest rate swaps | Bonds                  
Derivative [Line Items]                  
Derivative notional amount             $ 135,000,000    
Interest rate swaps | Senior Unsecured Notes                  
Derivative [Line Items]                  
Derivative notional amount             $ 300,000,000    
Interest rate (percent)     4.60%       4.60%    
Interest Rate Swap One | Ascendant                  
Derivative [Line Items]                  
Derivative notional amount $ 87,627,000                
Derivative, fixed interest rate (percent) 3.28%                
Interest Rate Swap Two | Ascendant                  
Derivative [Line Items]                  
Derivative notional amount $ 8,875,000                
Derivative, fixed interest rate (percent) 3.02%                
Currency Swap                  
Derivative [Line Items]                  
Derivative notional amount       $ 650,000,000          
Foreign currency gain (loss)   13,256,000 $ 0            
Foreign exchange contract                  
Derivative [Line Items]                  
Foreign currency gain (loss)   3,581,000 (35,277,000)            
Currency forward contract                  
Derivative [Line Items]                  
Derivative notional amount         $ 682,500,000 $ 923,243,000      
Foreign currency gain on settlement of derivative   2,363,000              
Non-regulated Energy Sales                  
Derivative [Line Items]                  
Unrealized gains in AOCI to be reclassified   8,624,000              
Interest expense                  
Derivative [Line Items]                  
Unrealized gains in AOCI to be reclassified   483,000              
Derivative gains                  
Derivative [Line Items]                  
Unrealized gains in AOCI to be reclassified   1,215,000              
Sugar Creek                  
Derivative [Line Items]                  
Amount reclassified from AOCI to earnings     15,765,000            
Canadian Investments and Subsidiaries                  
Derivative [Line Items]                  
Foreign currency gain (loss)   $ 656,000 $ 0            
Minimum                  
Derivative [Line Items]                  
Forward price | $ / MWh   13.64   13.64          
Minimum | AYES Canada | Measurement Input, Discount Rate                  
Derivative [Line Items]                  
Alternative investment, measurement input (percent)   0.0825   0.0825          
Minimum | Atlantica Yield Energy Solutions Canada, Inc | Measurement Input, Price Volatility                  
Derivative [Line Items]                  
Alternative investment, measurement input (percent)   0.22   0.22          
Maximum                  
Derivative [Line Items]                  
Forward price | $ / MWh   98.05   98.05          
Maximum | AYES Canada | Measurement Input, Discount Rate                  
Derivative [Line Items]                  
Alternative investment, measurement input (percent)   0.0875   0.0875          
Maximum | Atlantica Yield Energy Solutions Canada, Inc | Measurement Input, Price Volatility                  
Derivative [Line Items]                  
Alternative investment, measurement input (percent)   0.46   0.46          
Weighted Average                  
Derivative [Line Items]                  
Forward price | $ / MWh   22.96   22.96          
Weighted Average | AYES Canada | Measurement Input, Discount Rate                  
Derivative [Line Items]                  
Alternative investment, measurement input (percent)   0.0867   0.0867          
Cash flow hedge | Interest rate swaps                  
Derivative [Line Items]                  
Term of forward-starting interest rate swap     10 years            
Cash flow hedge | ISO NE Spot Rate contract expiring February 2022                  
Derivative [Line Items]                  
Number of Megawatt hours | MWh   81,408              
Cost per Megawatt Hour | $ / MWh   38.95