Accumulated Other Comprehensive Income (AOCI) (Schedule of Items Reclassified to Statement of Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Expense related to interest rate swaps included in Income before taxes	$ 17,835	$ 17,391	$ 16,332
Income tax effect	(35,472)	(47,163)	(41,831)
Effect on net income due to items reclassified from Accumulated Other Comprehensive Income	95,762	118,478	98,589
Prior service credit	(4,497)	(4,475)	(4,474)
Amortization of actuarial (loss)	3,260	4,625	5,004
Total pretax amount reclassified	131,980	165,931	139,074
Reclassification out of Accumulated Other Comprehensive Income | Derivative Valuation Adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Expense related to interest rate swaps included in Income before taxes	468	6,852	3,982
Income tax effect	(118)	(1,734)	(1,028)
Effect on net income due to items reclassified from Accumulated Other Comprehensive Income	350	5,118	2,954
Reclassification out of Accumulated Other Comprehensive Income | Pension and postretirement liability adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax effect	(16,051)	(52)	(276)
Effect on net income due to items reclassified from Accumulated Other Comprehensive Income	25,369	98	665
Reclassification of loss on pension settlement	42,657	0	411
Prior service credit	(4,497)	(4,475)	(4,474)
Amortization of actuarial (loss)	3,260	4,625	5,004
Total pretax amount reclassified	$ 41,420	$ 150	$ 941