Fair Value of Financial Instruments - The Waha JVs - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, equity in earnings (losses)	$ 8,714	$ 7,445	$ 23,585	$ 22,092
Equity method investments, net investment	250,000		250,000		$ 220,000
Unrealized gains (losses) on equity investee activity, net of tax	(1,041)	2,839	9,333	(21,447)
Waha JVs
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investments, equity in earnings (losses)	8,300	7,700	24,600	22,900
Equity method investments, distributions of earnings received, operating cash flows	4,400	2,400	4,400	10,200
Equity method investments, cumulative undistributed earnings	87,500		87,500
Equity method investments, net investment	206,000		206,000		$ 175,000
Unrealized gains (losses) on equity investee activity, before tax	1,800	2,500	14,100	(29,500)
Unrealized gains (losses) on equity investee activity, net of tax	$ 1,300	$ 1,900	$ 10,700	$ (22,400)