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 (Loss) Income [Member]	Total
Beginning balance at Dec. 31, 2018	$ 5,396	$ 101,663	$ 1,516,243	$ (597,800)	$ (165,555)
Beginning balance (in shares) at Dec. 31, 2018				11,731,223
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings			82,047			$ 82,047
Other comprehensive Income (loss)					2,547
Cash dividends paid			(62,190)
Share-based compensation		(739)
Non-vested stock issued upon vesting		(2,343)		$ 2,343
Non-vested stock issued upon vesting (in shares)				(45,981)
Benefit plans		72		$ 948
Benefit plans (in shares)				(18,597)
Other		(228)		$ (815)
Other (in shares)				15,991
Ending balance at Dec. 31, 2019	5,396	98,425	1,536,100	$ (595,324)	(163,008)
Ending balance (in shares) at Dec. 31, 2019				11,682,636
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings			109,472			109,472
Other comprehensive Income (loss)					3,917
Cash dividends paid			(66,057)
Share-based compensation		5,608
Non-vested stock issued upon vesting		(1,352)		$ 1,352
Non-vested stock issued upon vesting (in shares)				(26,515)
Benefit plans		241		$ 833
Benefit plans (in shares)				(16,344)
Other		(13)	(853)	$ (401)
Other (in shares)				7,850
Ending balance at Dec. 31, 2020	5,396	102,909	1,578,662	$ (593,540)	(159,091)	$ 934,336
Ending balance (in shares) at Dec. 31, 2020				11,647,627		11,647,627
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings			118,745			$ 118,745
Other comprehensive Income (loss)					(15,537)
Cash dividends paid			(66,694)
Share-based compensation		9,573
Non-vested stock issued upon vesting		(1,264)		$ 1,264
Non-vested stock issued upon vesting (in shares)				(24,711)
Benefit plans		338		$ 756
Benefit plans (in shares)				(14,791)
Purchase of treasury stock				$ (42,511)
Purchase of treasury stock (in shares)				492,045
Other		(204)		$ (377)
Other (in shares)				7,379
Ending balance at Dec. 31, 2021	$ 5,396	$ 111,352	$ 1,630,713	$ (634,408)	$ (174,628)	$ 938,425
Ending balance (in shares) at Dec. 31, 2021				12,107,549		12,107,549