Income Taxes - Income tax expense (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income tax expense
Current income tax expense (benefit)	$ (11,000)	$ (55,517)	$ (539)	$ 33,615
Deferred income tax benefit (benefit)		(171)	(101,927)	(1,304)
Total income tax expense (benefit)		$ (55,688)	$ (102,466)	$ 32,311