Quarterly report pursuant to Section 13 or 15(d)

Debt, Net - Fair Value of Debt (Details)

v3.21.2
Debt, Net - Fair Value of Debt (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Carrying Amount    
Carrying amount and estimated fair value of debt    
Long-term debt $ 2,159,732 $ 2,086,918
Carrying Amount | Unsecured senior notes    
Carrying amount and estimated fair value of debt    
Long-term debt 1,678,659 1,289,461
Carrying Amount | Other fixed-rate debt    
Carrying amount and estimated fair value of debt    
Long-term debt 138,101 140,891
Carrying Amount | Variable-rate secured debt    
Carrying amount and estimated fair value of debt    
Long-term debt 342,972 656,566
Estimated Fair Value    
Carrying amount and estimated fair value of debt    
Long-term debt 2,203,497 2,131,282
Estimated Fair Value | Unsecured senior notes    
Carrying amount and estimated fair value of debt    
Long-term debt 1,723,267 1,334,342
Estimated Fair Value | Other fixed-rate debt    
Carrying amount and estimated fair value of debt    
Long-term debt 136,653 142,838
Estimated Fair Value | Variable-rate secured debt    
Carrying amount and estimated fair value of debt    
Long-term debt $ 343,577 $ 654,102