Accumulated Other Comprehensive Income (AOCI) (Schedule of Items Reclassified to Statement of Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service credit	$ (1,123)	$ (1,119)
Net actuarial loss	971	1,109
Income before income taxes	39,073	37,649
Income tax effect	(10,998)	(10,040)
Net income attributable to the Company	27,737	27,582
Reclassification out of Accumulated Other Comprehensive Income | Derivative valuation adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Expense/(income) related to interest rate swaps included in Income before taxes	1,696	1,476
Income tax effect	(430)	(381)
Net income attributable to the Company	1,266	1,095
Reclassification out of Accumulated Other Comprehensive Income | Pension and postretirement liability adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service credit	(1,123)	(1,119)
Net actuarial loss	971	1,109
Income before income taxes	(152)	(10)
Income tax effect	47	3
Net income attributable to the Company	$ (105)	$ (7)