Pensions - Components of Pension Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Interest cost	$ 10,469	$ 13,949	$ 22,146
Expected return on assets	(11,560)	(16,027)	(15,044)
Settlement (gain)/loss	(374)	819	693
Remeasurement (gain)/loss	(13,364)	43,495	45,366
Net periodic pension (benefit) cost	$ (14,829)	$ 42,236	$ 53,161