Annual report pursuant to Section 13 and 15(d)

Credit facilities and commercial paper notes - Additional Information (Details)

v3.22.0.1
Credit facilities and commercial paper notes - Additional Information (Details)
 1 Months Ended 12 Months Ended
Feb. 28, 2022
USD ($)
Sep. 30, 2021
USD ($)
Apr. 30, 2021
USD ($)
Dec. 31, 2021
USD ($)
debt_instrument
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Mar. 31, 2021
USD ($)
Feb. 28, 2021
USD ($)
Line of Credit Facility [Line Items]                
Unamortized debt issuance costs (less than)       $ 10,000,000 $ 12,000,000      
Issuance of green commercial paper notes       $ 50,000,000 $ 0 $ 0    
Credit Facilities                
Line of Credit Facility [Line Items]                
Number of revolving credit facilities | debt_instrument       2        
Unamortized issuance costs       $ 2,000,000        
Default underlying financings (more than)       50.00%        
Credit Facilities | LIBOR                
Line of Credit Facility [Line Items]                
Default interest rate (in percent)       2.00%        
Credit Facilities | Rep-Based Facility                
Line of Credit Facility [Line Items]                
Maximum outstanding amount             $ 100,000,000 $ 250,000,000
Loss on modification       $ 1,500,000        
Availability fee percentage       0.60%        
Credit Facilities | Rep-Based Facility | U.S. Federal Government                
Line of Credit Facility [Line Items]                
Applicable valuation percentages       85.00%        
Credit Facilities | Rep-Based Facility | Institutional                
Line of Credit Facility [Line Items]                
Applicable valuation percentages       80.00%        
Credit Facilities | Rep-Based Facility | LIBOR                
Line of Credit Facility [Line Items]                
Basis spread on variable rate       1.40%        
Fixed interest rate (in percent)       1.85%        
Credit Facilities | Rep-Based Facility | Federal Funds Rate                
Line of Credit Facility [Line Items]                
Basis spread on variable rate       0.40%        
Fixed interest rate (in percent)       0.85%        
Credit Facilities | Approval-Based Facility                
Line of Credit Facility [Line Items]                
Maximum outstanding amount       $ 200,000,000        
Credit Facilities | Approval-Based Facility | Certain Approved Existing Financing                
Line of Credit Facility [Line Items]                
Applicable valuation percentages       85.00%        
Credit Facilities | Approval-Based Facility | Others as Prescribed by Administrative Agent                
Line of Credit Facility [Line Items]                
Applicable valuation percentages       67.00%        
Credit Facilities | Approval-Based Facility | LIBOR                
Line of Credit Facility [Line Items]                
Basis spread on variable rate       1.50%        
Fixed interest rate (in percent)       2.00%        
Credit Facilities | Approval-Based Facility | Federal Funds Rate                
Line of Credit Facility [Line Items]                
Basis spread on variable rate       0.50%        
Fixed interest rate (in percent)       1.00%        
Credit Facilities | Unsecured Credit Facility                
Line of Credit Facility [Line Items]                
Maximum outstanding amount     $ 400,000,000         $ 50,000,000
Long-term debt, term     364 days          
Outstanding credit facility       $ 50,000,000        
Interest rate       2.35%        
Unamortized debt issuance costs (less than)       $ 1,000,000        
Credit Facilities | Unsecured Credit Facility | LIBOR                
Line of Credit Facility [Line Items]                
Basis spread on variable rate     2.25%          
Variable rate, maximum downward adjustment (in percent)     0.05%          
Credit Facilities | Unsecured Credit Facility | Prime Rate                
Line of Credit Facility [Line Items]                
Basis spread on variable rate     1.25%          
Credit Facilities | CarbonCount© Green Commercial Paper Note Program                
Line of Credit Facility [Line Items]                
Interest rate       1.26%        
Credit Facilities | New Revolving Credit Facility | Subsequent Event                
Line of Credit Facility [Line Items]                
Maximum outstanding amount $ 600,000,000              
Term loan fee (in percent) 1.875%              
Credit Facilities | New Revolving Credit Facility | Prime Rate                
Line of Credit Facility [Line Items]                
Basis spread on variable rate     0.875%          
Credit Facilities | New Revolving Credit Facility | SOFR                
Line of Credit Facility [Line Items]                
Basis spread on variable rate     1.875%          
Credit Facilities | New Revolving Credit Facility | SOFR | Subsequent Event                
Line of Credit Facility [Line Items]                
Variable rate, maximum downward adjustment (in percent) 0.10%              
Commercial Paper | CarbonCount© Green Commercial Paper Note Program                
Line of Credit Facility [Line Items]                
Maximum outstanding amount   $ 100,000,000            
Credit facility remaining no of days   397 days            
Issuance of green commercial paper notes       $ 50,000,000        
Broker fee percent   0.0010            
Unamortized financing costs       $ 1,000,000        
Letter of Credit | CarbonCount© Green Commercial Paper Note Program                
Line of Credit Facility [Line Items]                
Maximum outstanding amount   $ 100,000,000            
Percentage of drawn letter of credit   0.0095            
Unused letter of credit capacity percentage   0.40%            
Reduced percentage of letter of credit Fee   0.0005