Accumulated Other Comprehensive Income (Loss) - Schedule of reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accumulated Other Comprehensive Income (Loss)
Interest expense	$ (3,120)	$ (4,060)	$ (10,783)	$ (16,245)
Net loss resulting from early retirement of debt		394	1,126	14,143
Interest and investment income	4,803	2,224	12,340	2,776
Total before tax	90,472	181,481	415,991	861,867
Provision for income taxes	16,781	474	66,839	1,424
Net Income (Loss)	73,691	181,007	349,152	860,443
Pension, postretirement and other post-employment benefits
Accumulated Other Comprehensive Income (Loss)
Provision for income taxes			3,419
Available-for-sale securities
Accumulated Other Comprehensive Income (Loss)
Provision for income taxes			(4)
Reclassification out of Accumulated Other Comprehensive Income | Derivative instruments
Accumulated Other Comprehensive Income (Loss)
Interest expense				(112)
Net loss resulting from early retirement of debt				(1,428)
Provision for income taxes	0	0	0	0
Net Income (Loss)				(1,540)
Reclassification out of Accumulated Other Comprehensive Income | Pension, postretirement and other post-employment benefits
Accumulated Other Comprehensive Income (Loss)
Amortization of actuarial gains (losses), net	2,792	571	8,509	1,544
Amortization of prior service credits	25	38	98	111
Pension settlement	6,953	201	6,953	615
Total before tax	9,770	810	15,560	2,270
Provision for income taxes	2,147	0	3,419	0
Net Income (Loss)	7,623	810	12,141	2,270
Reclassification out of Accumulated Other Comprehensive Income | Available-for-sale securities
Accumulated Other Comprehensive Income (Loss)
Interest and investment income	(40)		(61)	(182)
Provision for income taxes	(12)	$ 0	(4)	0
Net Income (Loss)	$ (28)		$ (57)	$ (182)