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, 2022	$ 5,396	$ 124,043	$ 1,702,700	$ (631,853)	$ (200,688)	$ 999,598
Beginning balance (in shares) at Dec. 31, 2022				12,058,773
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	0	0	33,651	$ 0	0	33,651
Other comprehensive income (loss)	0	0	0	0	16,301	16,301
Cash dividends paid	0	0	(17,255)	0	0	(17,255)
Share-based compensation	0	2,267	0	0	0	2,267
Non-vested stock issued upon vesting	0	(11,956)	0	$ 11,956	0	0
Non-vested stock issued upon vesting (in shares)				(228,181)
Benefit plans	0	375	0	$ 952	0	1,327
Benefit plans (in shares)				(18,172)
Other	0	(2,140)	0	$ (5,528)	0	(7,668)
Other (in shares)				105,524
Ending balance at Mar. 31, 2023	5,396	112,589	1,719,096	$ (624,473)	(184,387)	1,028,221
Ending balance (in shares) at Mar. 31, 2023				11,917,944
Beginning balance at Dec. 31, 2023	5,396	115,941	1,726,872	$ (622,768)	(172,117)	1,053,324
Beginning balance (in shares) at Dec. 31, 2023				11,885,398
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	0	0	30,940	$ 0	0	30,940
Other comprehensive income (loss)	0	0	0	0	(3,611)	(3,611)
Cash dividends paid	0	0	(17,312)	0	0	(17,312)
Share-based compensation	0	1,995	0	0	0	1,995
Non-vested stock issued upon vesting	0	(5,365)	0	$ 5,365	0	0
Non-vested stock issued upon vesting (in shares)				(102,396)
Benefit plans	0	299	0	$ 1,122	0	1,421
Benefit plans (in shares)				(21,405)
Other	0	(481)	0	$ (2,340)	0	(2,821)
Other (in shares)				44,652
Ending balance at Mar. 31, 2024	$ 5,396	$ 112,389	$ 1,740,500	$ (618,621)	$ (175,728)	$ 1,063,936
Ending balance (in shares) at Mar. 31, 2024				11,806,249