Fair Value Measurements - Derivative Instrument Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Asset derivative instruments, at fair value	$ 648,855	$ 527,073
Derivative instruments, at fair value	2,160,253	600,877
Fair value on a recurring basis | Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Asset derivative instruments, at fair value	134,691	70,603
Derivative instruments, at fair value	315,372	93,361
Fair value on a recurring basis | Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Asset derivative instruments, at fair value	514,164	456,470
Derivative instruments, at fair value	1,844,881	507,516
Fair value on a recurring basis | Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Asset derivative instruments, at fair value	0	0
Derivative instruments, at fair value	0	0
Fair value on a recurring basis | Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Asset derivative instruments, at fair value	648,855	527,073
Derivative instruments, at fair value	$ 2,160,253	$ 600,877