Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Details)

v3.20.4
Fair Value Measurements (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Fair Value on Non-Recurring Basis      
Amount outstanding $ 714,201    
Amount of transfers of assets and liabilities measured on a recurring and non-recurring basis between Levels 1, 2 and 3 of the fair value hierarchy 0 $ 0 $ 0
Senior Notes      
Fair Value on Non-Recurring Basis      
Amount outstanding 400,000 $ 400,000  
Fair Value on Non-Recurring Basis | Level 1 fair value measurement | Senior Notes      
Fair Value on Non-Recurring Basis      
Fair value $ 418,000