Long-term debt - Narrative (Details) - USD ($)			12 Months Ended
	Oct. 10, 2024	Nov. 23, 2020	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Sep. 19, 2024	Sep. 22, 2020
Debt Instrument [Line Items]
Cash paid during the year for interest			$ 88,795,000	$ 68,399,000	$ 22,810,000
5.50% Senior Secured Notes
Debt Instrument [Line Items]
Long-term debt gross			0	113,050,000
Interest expense, debt			4,800,000	6,200,000
Cash paid during the year for interest			$ 4,800,000	$ 6,200,000
5.50% Senior Secured Notes | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)							5.50%
Aggregate principal amount of debt issued							$ 125,000,000
Issue price (as a percent)							100.00%
Long-term debt gross	$ 113,050,000.00					$ 113,050,000.00
Redemption price (as a percent)	100.00%	99.80%
Debt instrument, repurchase amount						$ 11,950,000
6.75% Senior Secured Notes | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)							6.75%
Long-term debt gross							$ 150,000,000
Long term debt held in treasury							1,400,000
Long term debt outstanding, net of amount held in treasury							$ 148,600,000