Condensed Consolidated Statements of Changes in Retained Earnings, Accumulated Other Comprehensive Loss and Noncontrolling Interests - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 47,693	$ 25,186	$ 83,235	$ 61,636
Pension and post-retirement plan adjustments, net of tax	2,330	3,657	4,594	7,369
Income attributable to noncontrolling interests	0	(262)	0	(448)
Preferred dividends	$ (10)	$ (10)	$ (20)	$ (20)
Common stock, dividends (in dollars per share)	$ 0.46	$ 0.44	$ 0.90	$ 0.87
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,068,464	$ 1,122,722	$ 1,050,214	$ 1,103,092
Net income	47,693	25,448	83,235	62,084
Income attributable to noncontrolling interests		(262)		(448)
Common dividends	(18,099)	(17,237)	(35,381)	(34,047)
Preferred dividends	(10)	(10)	(20)	(20)
Ending balance	1,098,048	1,130,661	1,098,048	1,130,661
Accumulated Other Comprehensive (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(140,993)	(188,948)	(149,140)	(182,397)
Foreign currency translation adjustments	(31,606)	6,018	(25,714)	(4,205)
Pension and post-retirement plan adjustments, net of tax	2,330	3,657	4,594	7,369
Unrealized net gains (losses) on available-for-sale securities	(9)	1	(18)	(4)
Income attributable to noncontrolling interests		127		92
Ending balance	(170,278)	(179,145)	(170,278)	(179,145)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	8,214	0	7,993
Income attributable to noncontrolling interests		135		356
Ending balance	$ 0	$ 8,349	$ 0	$ 8,349