Condensed Consolidated Statements of Changes in Retained Earnings, Accumulated Other Comprehensive Loss and Noncontrolling Interests - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 35,542	$ 36,450
Pension and post-retirement plan adjustments, net of tax	2,264	3,712
Income attributable to noncontrolling interests	0	(186)
Preferred dividends	(10)	(10)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,050,214	1,103,092
Net income	35,542	36,636
Income attributable to noncontrolling interests		(186)
Common dividends	(17,282)	(16,810)
Preferred dividends	(10)	(10)
Ending balance	1,068,464	1,122,722
Accumulated Other Comprehensive (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(149,140)	(182,397)
Foreign currency translation adjustments	5,892	(10,223)
Pension and post-retirement plan adjustments, net of tax	2,264	3,712
Unrealized net gains (losses) on available-for-sale securities	(9)	(5)
Income attributable to noncontrolling interests		(35)
Ending balance	(140,993)	(188,948)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	7,993
Income attributable to noncontrolling interests		221
Ending balance	$ 0	$ 8,214