Investments in Other Entities and Noncontrolling Interest in a Subsidiary - NG Advantage (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Oct. 14, 2014
Schedule of Equity Method Investments [Line Items]
Loss from noncontrolling interest	$ 127	$ 282	$ 512	$ 560
Investments carried at cost	8,000		8,000
NG Advantage
Schedule of Equity Method Investments [Line Items]
Loss from noncontrolling interest	100	$ 300	500	$ 600
Noncontrolling interest, fair value	$ 7,800		$ 7,800		$ 8,300
NG Advantage | Common unit purchase agreement
Schedule of Equity Method Investments [Line Items]
Ownership interest acquired						53.30%
Ownership interest after transaction (as a percent)			93.30%