Significant accounting policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Gain (Loss) on Securities [Line Items]
Company contributed segregated account representing loss	$ 25,000,000.0
Total revenue	28,833,000	$ 38,025,000	$ 485,424,000
Cash	127,100,000	127,500,000
Cash equivalents	29,200,000	5,800,000
Restricted cash	27,300,000	27,300,000
Restricted cash current	25,000,000	25,000,000
Restricted cash current within other current assets	2,100,000	1,600,000
Restricted cash noncurrent	200,000	700,000
Marketable securities unrealized fair value (losses) gains	800,000	(2,100,000)	(1,700,000)
Non-marketable securities	32,300,000	32,300,000
Fair value gains	16,600,000	1,800,000	0
Allowance for doubtful accounts recorded	0	0	0
Amortization	9,400,000
Changes in amortization expenses	$ 600,000
Number of reportable segments | segment	1
Number of operating segments | segment	1
Goodwill	$ 47,806,000	47,806,000
Accumulated impairment	$ 0	0
Effective income tax related	50.00%
Canada
Gain (Loss) on Securities [Line Items]
Total revenue	$ 26,200,000	36,000,000.0	484,200,000
Long-term assets	85,700,000	429,700,000
Additions to property and equipment	69,100,000	19,600,000	137,300,000
U.S.
Gain (Loss) on Securities [Line Items]
Total revenue	2,700,000	2,000,000.0	1,200,000
Long-term assets	505,100,000	161,700,000
Other Foreign Countries
Gain (Loss) on Securities [Line Items]
Long-term assets	18,400,000	24,700,000
Research and development expense	$ 1,000,000.0	$ 0	$ 30,000,000