Fair value measurements - Schedule of Fair Value, by Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Fair value, balance sheet grouping [Line Items]
Long-term debt	$ 2,452,297	$ 2,298,223	$ 2,341,147
Carrying amount
Fair value, balance sheet grouping [Line Items]
Long-term debt	2,452,297	2,298,223	2,341,147
Fair value
Fair value, balance sheet grouping [Line Items]
Long-term debt, fair value	$ 2,207,359	$ 2,046,039	$ 1,960,926