Fair Value of Financial Assets and Liabilities - Schedule of Long Term Debt at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Cost
Fair Value of Financial Assets and Liabilities
Long-term debt, including current maturities, net	$ 1,065,109	$ 786,227
Fair Value
Fair Value of Financial Assets and Liabilities
Long-term debt, including current maturities, net	1,323,208	944,447
Fair Value | Level 1
Fair Value of Financial Assets and Liabilities
Long-term debt, including current maturities, net	0	0
Fair Value | Level 2
Fair Value of Financial Assets and Liabilities
Long-term debt, including current maturities, net	1,323,208	944,447
Fair Value | Level 3
Fair Value of Financial Assets and Liabilities
Long-term debt, including current maturities, net	$ 0	$ 0