Quarterly report pursuant to Section 13 or 15(d)

Debt, Net (Details 2)

v3.19.2
Debt, Net (Details 2) - USD ($)
$ in Thousands
Jun. 30, 2019
Dec. 31, 2018
Carrying Amount    
Carrying amount and estimated fair value of debt    
Long-term debt $ 1,784,362 $ 1,823,909
Carrying Amount | Unsecured senior notes    
Carrying amount and estimated fair value of debt    
Long-term debt 1,191,970 1,191,046
Carrying Amount | Other fixed-rate debt    
Carrying amount and estimated fair value of debt    
Long-term debt 146,388 148,308
Carrying Amount | Variable-rate debt    
Carrying amount and estimated fair value of debt    
Long-term debt 446,004 484,555
Estimated Fair Value    
Carrying amount and estimated fair value of debt    
Long-term debt 1,825,562 1,853,206
Estimated Fair Value | Unsecured senior notes    
Carrying amount and estimated fair value of debt    
Long-term debt 1,226,750 1,219,603
Estimated Fair Value | Other fixed-rate debt    
Carrying amount and estimated fair value of debt    
Long-term debt 148,395 147,106
Estimated Fair Value | Variable-rate debt    
Carrying amount and estimated fair value of debt    
Long-term debt $ 450,417 $ 486,497