Pensions and Other Postretirement Plans (Total Benefit/Cost) (Details 5) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 33,787	$ 32,567	$ 22,991
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Current year actuarial (gain) loss	(380,593)	727,097	(519,595)
Current year prior service (credit) cost	(11,263)	0	2
Amortization of prior service credit (cost)	(1,641)	(2,864)	(3,170)
Recognized net actuarial gain (loss)	42,146	70,833	5,486
Curtailments and settlements	1,087	0	120
Total Recognized in Other Comprehensive Income (Before Tax Effects)	(350,264)	795,066	(517,157)
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	33,787	32,567	22,991
Interest cost	46,211	30,504	26,917
Expected return on assets	(153,125)	(167,485)	(137,878)
Amortization of prior service cost (credit)	1,646	2,835	2,846
Recognized actuarial loss (gain)	(39,803)	(68,656)	(7,906)
Net Periodic Cost (Benefit) for the Year	(111,284)	(170,235)	(93,030)
Special separation benefit expense	9,886	3,624	1,132
Total Cost (Benefit) for the Year	(101,398)	(166,611)	(91,898)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Current year actuarial (gain) loss	(381,088)	749,258	(511,373)
Current year prior service (credit) cost	(11,263)	0	2
Amortization of prior service credit (cost)	(1,646)	(2,835)	(2,846)
Recognized net actuarial gain (loss)	39,803	68,656	7,906
Total Recognized in Other Comprehensive Income (Before Tax Effects)	(354,194)	815,079	(506,311)
Total Recognized in Total (Benefit) Cost and Other Comprehensive Income (Before Tax Effects)	(455,592)	648,468	(598,209)
Supplemental Executive Retirement Plan (SERP) [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	593	911	1,022
Interest cost	4,659	3,289	2,943
Amortization of prior service cost (credit)	0	36	331
Recognized actuarial loss (gain)	0	666	5,930
Total Cost (Benefit) for the Year	5,252	4,902	10,226
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Current year actuarial (gain) loss	909	(20,956)	(7,640)
Amortization of prior service credit (cost)	0	(36)	(331)
Recognized net actuarial gain (loss)	0	(666)	(5,930)
Total Recognized in Other Comprehensive Income (Before Tax Effects)	909	(21,658)	(13,901)
Total Recognized in Total (Benefit) Cost and Other Comprehensive Income (Before Tax Effects)	6,161	(16,756)	(3,675)
Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	149	98	92
Amortization of prior service cost (credit)	(5)	(7)	(7)
Recognized actuarial loss (gain)	(2,343)	(2,843)	(3,510)
Net Periodic Cost (Benefit) for the Year	(2,199)	(2,752)	(3,425)
Settlement gain	(1,087)	0	(120)
Total Cost (Benefit) for the Year	(3,286)	(2,752)	(3,545)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Current year actuarial (gain) loss	(414)	(1,205)	(582)
Amortization of prior service credit (cost)	5	7	7
Recognized net actuarial gain (loss)	2,343	2,843	3,510
Curtailments and settlements	1,087	0	120
Total Recognized in Other Comprehensive Income (Before Tax Effects)	3,021	1,645	3,055
Total Recognized in Total (Benefit) Cost and Other Comprehensive Income (Before Tax Effects)	$ (265)	$ (1,107)	$ (490)