v3.23.1
Debt - Long term (Details) - USD ($)
Dec. 31, 2022
Oct. 31, 2022
Oct. 01, 2022
Dec. 31, 2021
May 31, 2018
Long-term Debt, Current Maturities [Abstract]          
Carrying Value Long-Term Debt $ 1,191,100,000     $ 1,915,900,000  
Principal Outstanding 1,132,800,000     1,862,500,000  
Effective Interest Rate adjustments on PPL and Keppel Delivery Financing Facilities 19,800,000     17,100,000  
Deferred finance charges (6,400,000)     (6,500,000)  
PPL Delivery Financing          
Long-term Debt, Current Maturities [Abstract]          
Carrying Value Long-Term Debt 609,600,000     753,300,000  
Back-end fee, long-term 26,000,000.0     29,300,000  
Keppel Delivery Financing          
Long-term Debt, Current Maturities [Abstract]          
Carrying Value Long-Term Debt 259,200,000     259,200,000  
Back-end fee, long-term 13,500,000     13,500,000  
Hayfin Facility          
Long-term Debt, Current Maturities [Abstract]          
Carrying Value Long-Term Debt 134,000,000.0     197,000,000.0  
Back-end fee, long-term 2,800,000     0  
New DNB Facility          
Long-term Debt, Current Maturities [Abstract]          
Principal 150,000,000 $ 150,000,000 $ 150,000,000    
Carrying Value Long-Term Debt 130,000,000.0     0  
Back-end fee, long-term 2,600,000     0  
Syndicated Senior Secured Credit Facilities          
Long-term Debt, Current Maturities [Abstract]          
Carrying Value Long-Term Debt 0     272,700,000  
New Bridge Facility          
Long-term Debt, Current Maturities [Abstract]          
Carrying Value Long-Term Debt 0     30,300,000  
$350 million Convertible Bonds          
Long-term Debt, Current Maturities [Abstract]          
Principal 350,000,000       $ 350,000,000
Carrying Value Long-Term Debt $ 0     $ 350,000,000.0