Financial Assets and Liabilities - Level 3 financial instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other, net
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other, net
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 76,613	$ 81,358
Purchases	0	0
Total Realized and Unrealized Gains / (Losses)	5,192	(4,745)
Net Transfers into (out of) Level 3	0	0
Settlement	0	0
Ending balance	81,805	76,613
Change in Net Unrealized Gains / (Losses) on Investments still held at End of Period	5,192	(4,745)
Equity investment
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	76,613	81,358
Purchases	0	0
Total Realized and Unrealized Gains / (Losses)	5,192	(4,745)
Net Transfers into (out of) Level 3	0	0
Settlement	0	0
Ending balance	81,805	76,613
Change in Net Unrealized Gains / (Losses) on Investments still held at End of Period	$ 5,192	$ (4,745)