Fair Value Measurements - Instruments Not Recorded on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total debt	$ 1,376,986	$ 1,517,631
Fair Value | Senior notes | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total debt	564,916	576,875
Fair Value | Revolving credit facilities and term loans | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total debt	812,070	940,756
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total debt	1,319,099	1,450,234
Carrying Value | Senior notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total debt	519,651	519,211
Carrying Value | Revolving credit facilities and term loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total debt	$ 799,448	$ 931,023