CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Earnings Reinvested in the Business [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Beginning balance at Dec. 31, 2020	$ 5,396	$ 102,909	$ 1,578,662	$ (593,540)	$ (159,091)	$ 934,336
Beginning balance (in shares) at Dec. 31, 2020				11,647,627
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	0	0	31,668	$ 0	0	31,668
Other comprehensive loss	0	0	0	0	(15,139)	(15,139)
Cash dividends paid	0	0	(16,535)	0	0	(16,535)
Share-based compensation	0	2,113	0	0	0	2,113
Non-vested stock issued upon vesting	0	(563)	0	$ 563	0	0
Non-vested stock issued upon vesting (in shares)				(11,045)
Benefit plans	0	338	0	$ 756	0	1,094
Benefit plans (in shares)				(14,791)
Purchase of treasury stock	0	0	0	$ (11,665)	0	(11,665)
Purchase of treasury stock (in shares)				151,843
Other	0	(72)	0	$ (154)	0	(226)
Other (in shares)				3,020
Ending balance at Mar. 31, 2021	5,396	104,725	1,593,795	$ (604,040)	(174,230)	925,646
Ending balance (in shares) at Mar. 31, 2021				11,776,654
Beginning balance at Dec. 31, 2021	5,396	111,352	1,630,713	$ (634,408)	(174,628)	938,425
Beginning balance (in shares) at Dec. 31, 2021				12,107,549
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	0	0	37,071	$ 0	0	37,071
Other comprehensive loss	0	0	0	0	(237)	(237)
Cash dividends paid	0	0	(17,211)	0	0	(17,211)
Share-based compensation	0	4,163	0	0	0	4,163
Non-vested stock issued upon vesting	0	(2,478)	0	$ 2,478	0	0
Non-vested stock issued upon vesting (in shares)				(47,298)
Benefit plans	0	560	0	$ 618	0	1,178
Benefit plans (in shares)				(11,786)
Other	0	(624)	15	$ (1,070)	0	(1,679)
Other (in shares)				20,403
Ending balance at Mar. 31, 2022	$ 5,396	$ 112,973	$ 1,650,588	$ (632,382)	$ (174,865)	$ 961,710
Ending balance (in shares) at Mar. 31, 2022				12,068,868