Changes in Shareholders' Equity (Schedule of Activity in Shareholders' Equity) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Oct. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of the period	$ 867,543	$ 877,605
Net income	27,086	28,075
Compensation and benefits paid or payable in shares	378	745
Options exercised		7
Purchase of Treasury shares		(43,937)
Cumulative translation adjustments	14,119	(1,674)
Pension and postretirement liability adjustments	(916)	74
Derivative valuation adjustment	(2,902)	10,018
Balance at end of the period	$ 897,515	$ 864,252
Dividends declared per share, Class A and Class B (in dollars per share)	$ 0.25	$ 0.21
Stock repurchase program, authorized amount			$ 200,000
Common Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock, balance at the beginning of the period (in shares)	9,674,542
Dividends declared	$ (7,792)	$ (6,661)
Treasury stock, balance at the end of the period (in shares)	9,674,542
Dividends declared per share, Class A and Class B (in dollars per share)	$ 0.25	$ 0.21
Common Class B
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, balance at the beginning of the period (in shares)	0
Common stock, balance at the end of the period (in shares)	0
Dividends declared per share, Class A and Class B (in dollars per share)	$ 0.25	$ 0.21
Common Stock | Common Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, balance at the beginning of the period (in shares)	40,785,000	40,760,000
Balance at beginning of the period	$ 41	$ 41
Compensation and benefits paid or payable in shares (in shares)	58,000	21,000
Common stock, balance at the end of the period (in shares)	40,842,000	40,781,000
Balance at end of the period	$ 41	$ 41
Common Stock | Common Class B
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, balance at the beginning of the period (in shares)	0	0
Balance at beginning of the period	$ 0	$ 0
Common stock, balance at the end of the period (in shares)	0	0
Balance at end of the period	$ 0	$ 0
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of the period	441,540	436,996
Compensation and benefits paid or payable in shares	378	745
Options exercised		7
Balance at end of the period	441,917	437,748
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of the period	931,318	863,057
Net income	26,889	27,737
Balance at end of the period	950,415	884,133
Retained earnings | Common Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared	(7,792)	(6,661)
Accumulated items of other comprehensive income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of the period	(144,927)	(145,984)
Cumulative translation adjustments	13,881	(1,730)
Pension and postretirement liability adjustments	(916)	74
Derivative valuation adjustment	(2,902)	10,018
Balance at end of the period	$ (134,864)	$ (137,622)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock, balance at the beginning of the period (in shares)	9,675,000	8,665,000
Balance at beginning of the period	$ (364,923)	$ (280,143)
Purchase of Treasury shares (in shares)		514,686
Purchase of Treasury shares		$ (43,937)
Treasury stock, balance at the end of the period (in shares)	9,675,000	9,180,000
Balance at end of the period	$ (364,923)	$ (324,080)
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of the period	4,494	3,638
Net income	197	338
Cumulative translation adjustments	238	56
Balance at end of the period	$ 4,929	$ 4,032