Income taxes - Effective income tax reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
U.S. statutory federal corporate income tax rate	21.00%	21.00%	21.00%
Noncontrolling interest	(6.60%)	(6.40%)	(18.60%)
LLC flow-through structure	15.70%	5.40%	(70.40%)
Non-deductible expenses	(1.10%)	0.00%	43.80%
State and local income taxes, net of federal benefit	0.20%	4.20%	11.80%
Change in valuation allowance	(29.10%)	(0.40%)	7.00%
Research and other tax credits	0.50%	0.30%	(4.50%)
Organizational Transactions	0.00%	(0.60%)	(8.60%)
Uncertain tax positions	1.10%	(0.90%)	(9.00%)
Foreign rate differential	(0.20%)	0.00%	(0.90%)
GAAP impairment	0.00%	(3.50%)	0.00%
Stock compensation	(0.040)	0	0
Other	2.40%	4.40%	2.60%
Effective income tax rate	(0.10%)	23.50%	(25.80%)