Fair value measurements Debt (Details 5) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Fair value, balance sheet grouping [Line Items]
Long-term debt	$ 2,341,147	$ 2,365,667	$ 2,278,730
Carrying amount
Fair value, balance sheet grouping [Line Items]
Long-term debt	2,341,147	2,365,667	2,278,730
Fair value
Fair value, balance sheet grouping [Line Items]
Long-term debt, fair value	$ 1,960,926	$ 2,053,396	$ 1,989,362