Income taxes - Deferred income tax reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income tax (expense) benefit computed by applying the statutory rate	$ (31,217)	$ 184,405	$ 72,460
Change in deferred tax valuation allowance	45,717	(182,634)	(69,316)
Non-deductible equity-based compensation	(13,640)	0	0
State income tax and change in valuation allowance	(3,274)	2,903	1,863
Other items	(1,231)	(728)	(2,419)
Total income tax (expense) benefit	$ (3,645)	$ 3,946	$ 2,588