Shareholders' Equity (Schedule of Activity in Shareholders' Equity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 25, 2021
Beginning balance	$ 819,865	$ 702,689	$ 608,280
Beginning balance (in shares)	32,300,000	32,300,000
Net income	$ 118,768	$ 97,243	133,383
Compensation and benefits paid or payable in shares	2,441	622	1,311
Options exercised	153	55	112
Shares issued to Directors'	947	883	752
Purchase of treasury shares	(24,375)
Cumulative translation adjustments	(23,128)	40,788	(6,886)
Pension and postretirement liability adjustments	1,171	10,333	(2,885)
Derivative valuation adjustment	7,930	(6,409)	$ (7,832)
Accounting Standards Update [Extensible Enumeration]			ASC 326	Accounting Standards Update 2016-02 [Member]
Ending balance	$ 877,605	$ 819,865	$ 702,689	$ 608,280
Ending balance (in shares)	32,100,000	32,300,000	32,300,000
Stock repurchase program, authorized amount					$ 200,000
Retained earnings	$ 863,057	$ 770,746
Cumulative Effect, Period of Adoption, Adjustment
Beginning balance		(1,443)	$ 35
Ending balance			(1,443)	35
Retained earnings				100
Common Class A
Dividends declared	$ (25,520)	$ (23,651)	$ (21,818)
Dividends declared per share amount (in dollars per share)	$ 0.81	$ 0.77	$ 0.73
Common Class B
Beginning balance (in shares)	1,617,998
Dividends declared	$ (647)	$ (1,245)	$ (1,763)
Ending balance (in shares)	104	1,617,998
Dividends declared per share amount (in dollars per share)	$ 0.81	$ 0.77	$ 0.73
Common Stock | Common Class A
Beginning balance	$ 39	$ 39	$ 37
Beginning balance (in shares)	39,115,000	39,099,000	37,450,000
Compensation and benefits paid or payable in shares (in shares)	20,000	13,000	26,000
Options exercised (in shares)	7,000	3,000	7,000
Conversion of Class B shares to Class A shares (in shares)	1,618,000		1,616,000
Conversion of Class B shares to Class A shares	$ 2		$ 2
Ending balance	$ 41	$ 39	$ 39	$ 37
Ending balance (in shares)	40,760,000	39,115,000	39,099,000	37,450,000
Common Stock | Series B Preferred Stock
Beginning balance	$ 2	$ 2	$ 3
Beginning balance (in shares)	1,618,000	1,618,000	3,234,000
Ending balance	$ 0	$ 2	$ 2	$ 3
Ending balance (in shares)	0	1,618,000	1,618,000	3,234,000
Common Stock | Common Class B
Conversion of Class B shares to Class A shares (in shares)	(1,618,000)		(1,616,000)
Conversion of Class B shares to Class A shares	$ (2)		$ (1)
Additional paid-in capital
Beginning balance	433,696	$ 432,518	430,555
Compensation and benefits paid or payable in shares	2,441	622	1,311
Options exercised	153	55	112
Shares issued to Directors'	706	501	540
Ending balance	436,996	433,696	432,518	$ 430,555
Retained earnings
Beginning balance	770,746	698,496	589,645
Net income	118,478	98,589	132,398
Conversion of Class B shares to Class A shares			(1)
Ending balance	863,057	770,746	698,496	589,645
Retained earnings | Cumulative Effect, Period of Adoption, Adjustment
Beginning balance	(1,400)	(1,443)	35
Ending balance		(1,400)	(1,443)	35
Retained earnings | Common Class A
Dividends declared	(25,520)	(23,651)	(21,818)
Retained earnings | Common Class B
Dividends declared	(647)	(1,245)	(1,763)
Accumulated items of other comprehensive income
Beginning balance	(132,408)	(175,981)	(158,388)
Cumulative translation adjustments	(22,677)	39,649	(6,876)
Pension and postretirement liability adjustments	1,171	10,333	(2,885)
Derivative valuation adjustment	7,930	(6,409)	(7,832)
Ending balance	(145,984)	(132,408)	(175,981)	(158,388)
Treasury Stock
Beginning balance	$ (256,009)	$ (256,391)	$ (256,603)
Beginning balance (in shares)	8,391,000	8,409,000	8,419,000
Shares issued to Directors'	$ 241	$ 382	$ 212
Shares issued to Directors' (in shares)	(11,000)	(18,000)	(10,000)
Purchase of treasury shares (in shares)	285,286
Purchase of treasury shares	$ (24,375)
Ending balance	$ (280,143)	$ (256,009)	$ (256,391)	$ (256,603)
Ending balance (in shares)	8,665,000	8,391,000	8,409,000	8,419,000
Noncontrolling Interest
Beginning balance	$ 3,799	$ 4,006	$ 3,031
Net income	290	(1,346)	985
Cumulative translation adjustments	(451)	1,139	(10)
Ending balance	$ 3,638	$ 3,799	$ 4,006	$ 3,031